-Read the disclaimer pls :(
-If you have no idea what an enemy or upgrade does, go to the collection tab to see what they do without the hacker speak and clarity
-You move twice as fast running diagonally than in a cardinal direction. Early on you will probably want to move this way to weave your way out of a pack. Useful for distancing yourself away from bosses as well.
-Killing a boss without getting hit gives you the flawless bonus. You'll have a texbox appear over your head telling you that the requirement was met and rewards you with a free level up. Required to get the true ending.
-Learn the boss patterns early on. Instead of hyperfocusing on dodging each bullet as they come, try to find out what the safespots are instead and path to take. Yes even the infested bosses as the patterns and movement are the same but way tighter and bullet hell-like. That or you can just run away with enough movespeed
-Know when to use autoaim. Once your build goes online it should be fine to keep on 24/7, but early game be weary as it locks onto the closest enemy. If trying to escape being surrounded turn it off and try to break through in a diagonal direction to avoid being hit by taking advantage of the movement bonus and being able to to focus fire your way out
-There is a fast forward button - I honestly found this on accident because I didn't realize there was a scroll on options. It could be just me that is dumb but it's a godsend and I wish more survivor like games had it
-Go into configuration and I recommend adjusting these settings for ease of vision.

• Auto upgrade at full build - OFF - You want full control of your build. Some upgrades are more worthwhile than others.
  
• Screenshake - Turn it down, you actually want to see whats going on
  
• Hit flash - ^
  
• Weapon Visibility - ^ Especially once your build starts going you actually won't be able to see anything
  
• Permanent Hitbox - ON - Shows the hitbox of your CORE at all times. Otherwise you would have to enter sneak to see it
  
• Pixel Perfect - ON
  
• Manual antilag level - 5.0 - I want the game to be as stable as possible when weaving through hordes or bullet patterns so I keep this maxed.
  
• Low health effects - OFF - For visual clarities sake in case you are dying
  
• Group XP into cannisters - OFF - So apparently leeches can't grab XP cannisters. I didn't know that before recording my demo but it isn't really a deal breaker as showcased, but once you enter fight a boss it can be annoying to level 50 times in a row.

-Once you beat the game once by returning to earth a new button should appear right under the start button. Beating the game on each overdrive provides an additional skill point resulting in 25+5 skill points total

-Check out this other guide for statue effects. https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=3114710211
-In case you didn't read the top, I did not include the new 40 achievements that came with the Contamination as it was already done by the time I found out the update came out so please check out their guide here. https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=3433180252

CONTAMINATION UPDATE:With the addition of suits, weapons and additional skill points with uncapped OD and prestige it's possible to create stronger/more stable builds for way less effort. I'll still leave the the original writeup untouched to at least show my though process when picking items or for those who don't have everything unlocked.

If you have played for a bit and already unlocked some stuff getting the harder achievements has been trivialized so either pick-

Perfected suit and maybe reroll til core upgrade and maybe add +1 slot for cooldown
Optimized suit and pick 4 good items. I personally went with Missile pack, eel, parasight to help grab xp as well as maybe a digiwatch.
Just keep resetting runs til you get those items and you really only have to play the game for a minute or two before you scale to become so powerful that bosses die before they even get an attack out.

If you haven't done those certain challenge runs yet elemental suit works just as well. Just try not to fill item slots by upgrading slot 1 on levels and you can probably unlock the optimized suit (clear with 4 items max) in the same run.

Probably not optimal but it worked well enough that it took me 2 tries to get both the True ending and Flawless without having to clench my cheeks. We're funneling 2 skills as the power spike is huge. You probably need to try until the 2nd boss and past that its autopilot. At the end I'll attach a video to showcase the build so you can see the potential even if I get hit.

The name of the game is single target DPS by stacking crit, parasight, and shock
Core weapons

• Parasight - Primary damage dealer - ALWAYS pick
  
• Missile Pack - Big DPS both AOE and single target - high priority
  
• Electric Eel - The item that puts it all together. Stun chance+dmg and with the amount of bullets we'll be shooting it allows us to stunlock bosses in place to ensure we shred bosses in seconds. - high priority
  
• Telecom/Shrapnel - Splash damage enabler - Level enough to where you're comfortable
  
• Angel Wings - Hitscan knockback. Can even hit things offscreen, The earlier you get this the sooner you can toggle fast forward and afk until the boss. I usually stop leveling around 8 or when I feel like i can handle hordes.
  
• Digiwatch - Makes everything shoot faster which is a no brainer. More shots = more crits and waveclear
  
• Eye2 - Piercing laser that hits very fast and used to proc eel and fish for crits.
  
• Injection - Bigger AoEs are nice to have
  
  Up to you
  
• Core - Our shotgun blast that allows us to clear horde in a single direction. Low priority
  
• Energizing Battery - Faster travelling bullets to make things more likely to hit. Especially helps with parasight moving between targets, flamethrower flame lifetime, and bow shots. Not very necessary depending on how build is going due to large aoes
  
• Shinobi Equipment - Line cleave that spreads its shots in a cone in front of you. Honestly prefer it over the leg saw since it can potentially proc multiple times. I like using it as a way to transition to ~10 mortality but stop upgrading it later
  
• Hunter's Bow - Guaranteed poison damage for salt the wound and homing properties. Nice to have but I would prioritize the above weapons instead.
  
  Why I don't take melee weapons,
  While they helped me get my first wins, I found that by the 10-15 mortality mark, enemies started to die even outside of the range of my leveled plasma belt and slime spikes even on OD5 so I decided to drop them for support items and its fine

If you are NOT max leveled the build above should still work perfectly well. You might have to actively play for 4 more minutes if anything. If you lack skill points I would prioritize movement, statues and drills then xp.

• RGB Genetics - Base skill
  
• Spaghettification - Synergizes with the following skills and used to get yourself out of sticky situations
  
• No worries - 3% weapon size per blackhole ain't bad. Normally you don't even need to use
  
• Scavenger - Allows you to horde more blackholes to stack the passive.
  
• Salt the wound -Free damage. Will be procced by flamethrower or shock eel
  
• Battery Lick-Kind of neat to have at the very beginning just to lock enemies in place sometimes. Probably better spent elsewhere tbh
  
• Marathon-Move speed. Basically almost always on
  
• Exponential Expedition- Scaling movespeed boost as the run goes on. Good to have
  
• Black atomization - Black holes vacuum enemies
  
• Hot Pursuit 10% extra CDR while moving meaning shoot faster
  
• Stack Overflow - I'd rather take this over Overheat because I almost never had the need to use a blackhole. Also nice to have if you're trying to focus fire a fish or elite and it dies instantly
  
• Hunting Season - Faster boss = better chance at flawless
  
• Nitrous - Doesn't seem like much but once you have more projectiles on screen and CDR it starts to add up
  
• Feeling Lucky - Your crit passive. Needed for the next 2 skills
  
• Critsplosion - Self explanatory. More crit = more aoe
  
• Overkill - What allows you to chunk bosses and kill in seconds
  
• Remnants of what was - Guarantees a statue spawn, see the other guide for effects
  
• Driller enhancement - I usually spend my rerolls for crit enhancements. If I don't get what I want I usually go for size, speed, cooldown or XP
  
• Magnetosphere - Needed to grab
  
• Leech education - Find it to be the best in the category as we're going to scale leeches anyways.
  
• Shocking Results - Free levels are always nice.
  
• Connect Call - Your free magnet right before every boss.
  
• Reversal Core - Gives your CORE shots a second chance to hit if they miss or overclear the screen. Nice to have before your projectile speed is quick enough full autoaim bosses
  
  The next few skills I had slotted but I think you can swap based off playstyle or preference but
  
  
• Plan and execution - If you get the right weapons you will probably be able to begin afking about halfway before the 2nd boss and weapon size is nice
  
• Expert - More levels is nice
  
• Blood soaked sword - Same as above. Getting a flawless isn't so bad
  
• Gaiden - RNG based get out of jail free card. Slot it in when going for True ending or the no hit run
  
• Meal to Go - 30 health after every boss. Personally I just used as a safety net once I blew all my HP on desperation statues. Otherwise not needed
  
• Ban #1 - Helps make the item pool smaller to get your build online faster to hit the item limit. Not the end of the world if you get a few items that you don't want so it's not mandatory
  
• Backwards core - An extra projectile helps clear at the start of the game.
  
  Honorable mentions - Can probably swap one of the above skills in the section above based on playstyle
  
  
• Bullet Time - Nice to have as a crutch but not really needed. Otherwise grab it if you have trouble dodging certain patterns.
  
• Fast Core - Nice to have for boss autoaim but not needed

-Spend rerolls for the crit honestly. It helps mow down hordes via critsplosion and shred bosses via Overkill. Just be mindful of the max hp debuff. If unavailable MS,CDR,HP, or proj size is nice

For the sake of brevity I'll skip out on the achievements that you earn naturally by just by beating the game up to Overdrive 5 as well as anything related to leveling a weapon to 8.

Harbinger - Bring the head of the 1st boss to the beginning of the final boss. - Not as hard as it sounds if you follow the build guide.
Once you kill the rabbit look out for this floating around. You will become best friends for the rest of the run. She constantly floats around and has her own center of gravity.
I found it best to slow her down by stopping right in its path and then to really slow her down I would enable bullet time to get in her center of mass. If you have to move away to reposition for a boss fight or to grab items it's usually no problem. For bosses you tend to kill them so fast she barely moves a half screen away but in case you do have to run away just remember where you left her :)

I'm in! - Enter debug mode. - As easy as pressing tab + F1 in the menu or ingame. Unsure if clearing the game once is needed to access. You can also use this menu to enter cheat codes but from what I read it disables achievements and I don't know any codes anyways so you'll have to look elsewhere.

Vlambeer - Go into configuration and set Screen Shake + Hit flashes to 2. Useful for triggering an epilepsy IRL.


Snake - Kill the worm without splitting it. - Best to turn off autoaim and aim at its head at all times. Just be wary if Parasight somehow latches onto a center piece it can potentially split the boss due to focused single target damage. Usually earned naturally with the build mentioned above.


- Keep track of these via the info dock and can supplement via drills if crit isn't wanted. Endless runs work too if you don't hit the target

Armed - Beat a run with 10+ Blackhole slots. Naturally obtained with Scavenger



Bleed - Beat a run with 200%+ Vitality - Grab an IV bag and spec some points into Meal to Go, The good stuff, and Organic Salvage. Can potentially go all in via Eating green, Cannibalistic, and Strength is Power for the specific run.


Speed - Beat a run with 200%+ Velocity - Get the Overcharged Engine to vroom vroom harder. More than likely will have Marathon and Exponential Expedition to supplement without having to dedicate a full run to it especially if you want to cheese the bosses.


Enlarge - Beat a run with 200%+ Attack Size. - Grab injection. It's a great passive anyways



Reach - Beat a run with 200%+ Pickup Size. - Pleonexic Crown and any skills on the tree that increase XP radius. Exponential Experience alone gives 50% radius by the end of the run.


Bullet - Beat a run with 200%+ Projectile Speed. - Get Energizing Battery

Experimental - Beat a run without upgrading CORE. - Don't really have to go out of your way to dedicate a run to this. Can easily get going for the others first.


Lightgun - Beat the game with Core, UltraBuster, Eye2 and Hunter's Bow. - If you follow my build guide you'll get this.


Mob Grinder - Beat the game with Slime Spike, Chainbelt, LegSaw and Hydrocillator. - Can probably pair this with the Manual achievement for no auto-aim


Offensive - Beat a run without using Halos or IVBags. - Just don't grab them. Not that hard to achieve.


Armed - Beat a run with 10+ Blackhole Slots. - Naturally obtained via Scavenger skill.



Revolution - Beat a daily. - Unlocked once you clear the game once. I unlocked the following 3 achievements at once by going for the loop at the end and it still counted.



Deja Vu - Reach 30 Mortality. - Just walk left and survive bro



Into The Unknown - Reach 40 Mortality - See above



Conqueror of the Abyss - Reach 50 Mortality - See above


instance_destroy(obj_boss_ghost); - Defeat the Ghost. - To fight the boss first you want to enter a zone with the mutation that spawns the ghost with a funny face that kills you in one hit if it touches you. The zone looks like this


Next is to lure the ghost onto an HP vial and that will spawn the secret boss. The best way to go about doing this is to grab the passive Meal to Go which spawns HP capsules on a boss kill and enter the zone. Run back to the capsules, lure the ghost, and get close to the materialized boss. In the end it's all RNG so you might have to go for a few runs to do this. If going for a no hit run I wouldn't recommend touching this boss at all because I think it's actually kind of difficult.

instance_destroy(obj_boss_yuki); - Defeat Yuki. To fight this secret boss chain bomb the Gambler statue. Look for a zone with this statue.



She's a pretty simple boss that gives rewards for killing her. I personally try to go for the kill so long as the enemies I have to face in the zone aren't a hassle. Dodge the icicles she fires at you and stay across from the field. Watch out for her charge attack and run diagonally. During phase 2 pay more attention to which side she's going to pop out and try to gain distance as quick as possible. Probably the easiest boss to flawless next to Bunny.

Well Rested - See the true ending. - Requires you to flawless the first 4 bosses and kill Picayune. (It's okay to get hit at any phase during the final boss). Flawless means you cannot get hit during any of the boss fights.Follow the build guideline and this should be free. Pop a blackhole whenever you feel unsafe as you should have way more than you need. The only boss that I ever had trouble dealing with was Demon as getting into position to dodge her patterns can be kind of weird. Sometimes I would accidentally trigger her teleport by running too far away essentially killing the run since I would be hyperfocused on dodging her patterns. Thankfully with good RNG you can kill her before it can become an issue or you can spam bombs off cooldown. Once Demon is down all that's next is to kill the final boss getting hit as many times as you want. I got hit every phase on accident due to brainrot and I still triggered the true ending sequence. Enjoy
Wow we saved everyone :)


Flawless - Beat the game without being hit by an enemy or boss or bullet.

Just don't get hit lmao

At the end of the day this is a roguelike so it'll take a bit of RNG and planning to get this done.

• Try to fill out your item list first. By hitting item cap you get more chances to level up the items you want earlier on. Don't be afraid to grab a statue of Discipline and ban the items you don't want if applicable.
  
• Pay attention to statues - I haven't seen it happen yet but I swear no matter what there will always be at least 1 chain bomb that spawns to blow up a statue. If you don't completely use a statue I personally blow up each one as I don't really worry about curse but the notables I like to watch out for are
  
  • Berserker - Raises curse but raises 3 random stats
    
  • Consequences - Gives free levels at the cost of making the next boss harder. Basically free 4 level ups if you grab it for the 1st,2nd or 3rd boss. Can also tap 3 times and chain bomb for curse. Do not recommend grabbing for Demon.
    
  • Distribution - If you have an item you don't like you can swap it for whatever shows up on the side. Useful for getting rid of something you don't like
    
  • Discipline - Really just want it to lower the item limit to get your build up faster
    
  • Gambler - Spend your dice for a level up - Even more levels and a drill enhancement if you blow it up for the secret boss.
    
  • Trade - Just wait til the exchange hits a level up and keep going til you have 1 tap left. Spend the last one on a chain bomb in case you don't find one for the rest of the level to get a free level up. I value the levels over black hole safety net.
• Pay attention to your build and what you need in the moment. Try to get things to wave clear early on while filling out your build. When loading into the game try to get a weapon that you'll use for the rest of the run. Don't waste rerolls and just reset if you don't see what you want. I try to get weapons over passives and aim for wings/shinobi to ease me into midgame. Once I feel like I have the horde controlled I start to focus my upgrades on weapons that can single target for boss kill speed.
  
• Try to fill out your items as soon as possible by taking the items you know you want by endgame. Every level up you tend to get at least 1 item you currently have +2 items that you may/may not own. By filling up early/removing max item count it enables you to have more chances to target farm the harder hitting items. Focusing on a few items is incredibly strong
  
• On curse - I normally don't worry about it with the build I run. The usual run killers (Cursed fish) dies before it even gets in XP range. Worst case just turn off autoaim and point. If you are having issues however forgo blowing up statues or grabbing ones with the curse aura on it.
  
• If applicable, try to do it on higher OD. You get more xp in general due to how the game scales. It's still very possible to do on NG or lower OD but you might have to actually play the game for an extra 3-4 minutes to get necessary upgrades.
  
• If you think you can handle it, always go for modified areas unless a no-no enemy is present. The only one I would be worried about is wisps on death if you don't have the AoE. Again be mindful of your current upgrades but if you think you can power through it more XP = more levels = more wave clear = faster boss kills

ROUTE WELL. In case you didn't know whenever you enter a new zone the enemy shown in the corner of the zone starts to spawn for the rest of the run. That being said this is my personal enemy tier list


Droid - Can fire a projectile which we don't want. If using my suggested build the LAST thing we want to do is actually play the game. The worst thing that can happen is if we try to dodge a bullet and walk right into a mob.







Sniper - Same as above







Warper - Once you are at the point of your build that you can afk they aren't too bad except for the fact they can teleport in front of your face. If you aren't paying attention you may accidentally walk into one while trying to collect things



- Okay to pick but be mindful of your own build and stage of the game

Dorito -Normally not an issue but can be a pain early game since they can suddenly dart straight out of a pack right into you.





Shielder - Just makes other mobs tanky. If you don't have the damage yet your worst nightmare is a cursed fish with a shield charging straight at you.







Wibbler - Just don't move and you're fine but early-midgame if you don't have the damage to screen clear they can easily close the distance and tag you.






Spider - Same reason as above but not as bad.







Face - Do not recommend encountering early on. Hitting them once activates them to move much faster. If you don't have the damage to kill them quickly and hit an unactivated face in point blank range, the sudden speed increase can throw you off and end the run. Along with the other high speed enemies, it can get pretty annoying when they start shoving eachother towards you.




Now to finish it all off an example video where I manage to meet conditions for both achievements in a single run that was supposed to be a build showcase. Keep in mind this is pre-contamination and you can easily do something even more busted but the build still performs
I kind of spaced out at 9:16 and nearly took damage but it worked out in the end. By the 11 minute mark I started to get more comfortable with full afk+autoaim often as the run went by. As you can see the bosses basically died before their 2nd attack pattern nearly trivializing the difficulty of this achievement.
Since the bosses kind of blow up in my own demo you can refer to this guide to see advice on boss patterns as I won't bother retyping info here. If going for no hit just blackhole it away. If going for true end DPS away or learn how to dodge.
https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=3116132139

Playing the game at my own pace and for fun I got all the achievements done in 19 hours and about 52 runs total. This was before I figured out my own winning combo for the final 5 or 6 runs before the 100%. Again I'm pretty sure there are other combinations that work better but this is what worked for me with the least amount of effort as shown in my demo video. Hope everyone has fun playing the game.

Banger OST, godlike aesthetics, and I love bullet hells
Game is fun and my biggest complaint is that it's over :(

It was fun enough that I felt like writing a guide for the first time so if there is anything I missed or suggestions to be made please do tell as I typed and recorded gameplay all in 1 sitting.