This guide is a work in progress and based on my own testing through various runs. There is very little documented about this game online, so I decided to try and figure it all out myself. Some of the shop upgrades are self explanatory, but since I haven't datamined the hard numbers, things like damage or firerate can sometimes be more of an assumption than a hard fact.

Let's start by looking at the in-game manual screen...


While this is probably good enough for most, I still found it kind of confusing for several reasons. Firstly, due to the vast amount of collectables, the manual has been delegated to the "museum" tab instead of having it's dedicated menu option. This is compounded on by the fact that there exists a tutorial, so for a while I didn't even know that a manual existed for this game! I also didn't fully understand how the upgrade system works as it's fairly vague, so I assumed that you had to perfectly time and choose which upgrade you wanted for your gun- that assumption is why I started writing this all down in the first place! So in case you are confused like I was, I want to make it clear that picking up a weapon upgrade upgrades all listed aspects of the relevant gun.

My goal with this guide is to demystify some of how your guns upgrade, and also give a tiny bit more insight on how you might use them throughout your run. I'm not an expert on this game by any means- I just really like it and was perplexed at the lack of info on it anywhere.

The Fore Gun fires straight in front of you, plain and simple. The bullets get a bit larger as they travel further, and moving up and down slightly curves the trajectory. Firing when charged shoots a slower, fatter bullet, which continues for a short while after contact before exploding violently. Fire then resumes back to the normal shot.

Generally all purpose, provided the enemies are in front of your ship.

Power ⇢ Wave ⇢ Curve ⇢ Blast ⇢ Guard

• Generalist, high power gun that never lets you down. Usually upgrade this or the aft gun first.
  
• Upgrading can be good for vertical levels and clearing out hard to reach packs of enemies due to curve and wave, but don't neglect your upper and lower guns either!
  
• Upgrading for Blast can really help the penultimate level, right before Leopold Grenade.
  
• In theory the fore gun is the best suited role to utilize guard, but usually I notice the aft gun absorbing way more bullets due to it's tail-like nature. Will still save your life occasionally though.

The Lower Gun is definitely the most unique weapon in Dezatopia, and probably requires the most explanation. While firing, small pellets of water come out of your ship in a spread pattern, constantly pelting enemies below. Firing when charged causes your first bullet to be a massive water droplet, which is very slow, deals higher damage, and breaks on contact.

The strange thing about the lower gun is that it's also used for utility- watering plants for animals is almost just as important as killing enemies with it. That much is taught in the tutorial, but the other oddity with it is it's unique "stow mechanic". Whenever you put your gun away, all of your water-bullets currently on screen cancel into water spears, which shoot in the direction of the closest enemy. This also happens automatically when water-bullets touch water... but not your water, the water found throughout some stages... augh, this is getting confusing...

Surprisingly powerful, considering there are a lot of situations where enemies are below you. I find that the smaller water bullets are not as exciting to use, so I tend to charge up a bunch of big droplets to send down instead. Watering plants is best achieved with the small ones though.

Break ⇢ Twin.L ⇢ Quick ⇢ C.Body ⇢ Guard
Just letting you know in advance: due to how weird this weapon is, this is definitely the gun I have the least information on. Thankfully some upgrades seem easy enough to understand, but I don't have a good grasp on things like damage, firerate, numbers, etc.

• If you are doing a level that contains a lot of water, upgrading for Twin.L is a must! The split-shots that are created from water-water contact are great at higher levels.

The Aft Gun is a waggly tail that follows you as you move, and shoots bullets from it's tip at the closest enemy. It's slower and less powerful than the front shot, compensating with it's auto-aim capabilities. Where it really shines though is it's charged shot- it shoots a wide shotgun blast of many bullets before transitioning back to the original firing mode.

The aft gun can also be "aimed" to shoot in front of you, but I find this too inconsistently difficult to use often. With enough practice it could be used to increase damage from any direction.

Power ⇢ B.Fire ⇢ Homing ⇢ Drill ⇢ Guard

• The aft gun is the sleeper hit and is generally the one I aim to get the most upgrades for. Starts out weak, but rapidly ramps in both damage and utility. Drills are awesome, shotgunning mechs with your charge blast is awesome, and it deals a lot of damage.
  
• Guard is also surprisingly useful for this thing too, as it's often close to your hitbox and moves around a lot.

The Upper Gun is a mortar shot that fires in an arc, exploding on contact. The charged shot shoots a small cluster of shots before resuming normal fire. It's a very simple weapon, but difficult to use.

It feels like the upper gun deals the highest damage out of any of your weapons at the start of the game, however its high difficulty curve and lack of power scaling seems to leave it in the dust after a few stages. The explosions it causes are great for cancelling bullets, if they manage to hit something... at the very least it does decent boss damage if they're hovering above you.

Spread ⇢ Length ⇢ Quick ⇢ Reflect ⇢ Guard

• I more or less never get upgrades for this thing unless I'm capped on money and have no other options. Its use case is far too specific and it doesn't seem to increase in power much. The one saving grace for it would be if any of these powerups increase it's damage, but I haven't noticed anything during testing.
  
• This sounds like a perfect opportunity for guard to finally shine, but a bullet approaching from directly above WHILE you have this weapon out happens less often than you'd think. And even then, your back gun might also be in a position to deflect bullets instead. Might be decent in the tower climb.

Life is fairly self-explanatory, the cheaper ones give you one refill on your life bar while the more expensive ones named "MAX LIFE" fully heal you.

"MAX UP" increases your maximum life, but it costs the same price as a weapon upgrade. Whether you get additional life or a better weapon is up to you, but i'd personally rather have better guns unless i'm in a dire situation or the other upgrade choices i'm given are bad. Your max health doesn't reset when you die, so if you manage to get one during a boss fight you know you'll lose a life on you'll have extra life going into the next attempt.

Bombs make you invincible for a long period, and deal high damage in a horizontal line. Unlike most other shmups/STGs, they don't reset on death. However, being capped on bombs when you die means you'll lose out on the bomb you get from respawning.

Bomb level seems to increase the damage, but consider that a WIP.