This guide contains SPOILERS for gameplay mechanics. The game unfolds its various mechanics (locked towers, unseen mechanics such as Artifacts), although rather quickly. It is recommended you play a map at least once; or develop your own playstyle until around Level 20 when you've fully unlocked the towers.

This is also a living document -- I've only played the game a few hours and completed only roughly half of the maps. It's still WIP but I'm publishing the guide now while I mentally take note some tips while I play the game.

If you'd like to correct any unintentionally harmful tips or if you'd like to suggest tips of your own, we can add them to this guide!

• Recommended turrets don't automatically mean they're the *best* turret for the job. Given the right technique, you can absolutely complete the map deviating from the recommended turret -- one example here is I've finished the map Gemini without using Blasters at all.
  
  
• You can more easily see how much damage you're making by enabling Options > Visuals > Health Bars for the relevant objects. In my game, Health Bars: Creeps was off by default.
  
  
• Maps are NOT strictly ordered by difficulty. Some maps are more difficult than others, and for the most case this is due to playstyle. Maps are harder on a person-to-person basis. Factoring in Artifacts, you'll perform better in certain maps later in the list order.
  
  
  
  
  
  
  
  
  
• Always, ALWAYS take note of which enemies you're facing. It's not that difficult to keep track of special enemies, but I'd like to present a notable few (in rough order of priority):
  
  • Fusers. You'll find yourself playing on a map with multiple Creep Hives (enemy spawn points) and soon enough you'll find yourself in the game over screen not knowing what happened. Fusers from different creep hives grow insanely stronger when they "touch" Fusers from other Creep Hives. This pressures you to play in a way where you should separate each Creep Hive's lane -- or devise a way to kill the Fusers before they reach a convergence point.
    
  • Porters. The bane of long hallways. If your map has only two turning corners, then it's as if Porters just traveled two blocks. Be mindful of Porters and build snaking corners near your turrets to counter these.
    
  • Phasers. No need to put Cloak Detection on all of your Blasters -- I tend to have a few turrets with Cloak Detection (or a Plasma Gate / Snap Trap) at the middle or tail end of the map to focus-fire on these cloaked creeps.

• Rely on Brian jar always. The main character is very powerful, and in emergencies you can change its Sort to First. Always ensure your Brian Jar is always in range of an enemy and is always shooting.
  
  
• The name of the game is managing Upkeep Tax. The earlier you build something, the more expensive it actually is. An extreme example is building a Blaster at Wave 1 versus fully upgrading an SRM at Wave 20 -- believe it or not these two "cost" around the same.
  
  
• The game incentivizes building as few structures as possible, as late as possible.
  
  • For a bit of math, the Blaster turret has an Upkeep Tax of 0.6% right out of the gate. Sure, you can build an army of them before Wave 1 even starts, but if you're going to earn, say, 40,000 Cred over a single run, you'll be wasting around 40,000*0.006=240 Cred just by the fact you built the turret.
    
  • With the same 40,000 figure, you're also wasting 40 creds just by building a single wall on Wave 1. Imagine the Creds you've wasted pre-building that maze on Wave 1.
  
  
• Make sure you're making your structures work for their worth. Towers and structures should be in use ideally 100% of the time. Ground Pounders should always be hitting creeps, Ranger turrets should always be head-shotting Brutes, and your Blaster turrets should be killing Runners around the clock. A turret you place out of range of an active enemy zone is essentially thousands of Creds wasted in the long run.
  
  
• Speaking of range, ensure all turrets have desired line of sight. Lack of line of sight is indicated by the red eye icons with the "X" mark. Note that this icon does not show up on scaffolding/incomplete tiles.
  
  
• Build turrets on top of walls, but not always. Walls can give you clearance on line of sight, like the image on the right, however...
  
  
• Be mindful of blocking your own line of sight. ALL structures, block each other's line of sight. The biggest offender here is the Boost Emitter, which blocks all turrets on the same level, even if they're placed on top of a Wall. While the Artillery turret shoots overhead, ignoring these restrictions, its projectiles tend to hit wherever sometimes, wasting shots (noticed on Decks map).
  
  
• On the topic of line of sight, the Pulser does not see through walls. I thought it did, maybe you guys thought so too. Its projectiles can phase through solid objects yes, but it won't fire without a target it can see.
  
  
• However, when you unlock the Quantum Farm, I recommend building it right off the bat and upgrade it occasionally.
  
  • When? The Quantum Farm pays for itself but NOT FOREVER. Note that it has an Upkeep Tax of 2%, and a starting Cred Per Wave of 20.
    
  • To break even, the Cred Per Wave should overcome the Upkeep Tax multiplied by your income per wave.
    
  • An easy way to check this is mentally figure out Cred Per Wave / Upkeep Tax. In this case, it's 20 / 0.02 = 1,000. Which means, I can upgrade the Quantum Farm no later than when I start earning 1000 Cred per wave. Of course, If I upgrade earlier, I'll get the returns earlier, but it's money I'm not spending on immediate survivability.
    
  • If you still don't get it, if I leave the Quantum Farm at level 1, and I'm gaining 2,000 Creds per wave -- I'm losing 40 of the 2,000 due to Upkeep Tax, even though I'm earning 20 Cred Per Wave. So, in essence, I'm losing 20 Cred per wave because the level 1 Quantum Farm's Cred Per Wave is so low it can't offset the upkeep.
  
  
• Focus on putting your firepower at the start of the wave.
  
  • The game also incentivizes killing the creeps as soon as they spawn.
    
  • If this isn't obvious yet -- the Roamer creep's sole purpose is to linger around as long as possible, inflating the population.
  
  
• Clear all Junk.
  
  • Clear all the Junk. Even if you think the Junk could substitute for a Wall in the creeps' path.
    
  • Even though Walls are expensive (though they're just 15 Cred each, they eat up 0.1% of your Cred the rest of the game), there's no telling when the unnoticed and/or unintended removal of Junk due to AoE attacks would mess your path up. Usually caused by Artillery turrets.
    
  • Junk is also essentially free Cred! The flying creeps that spawn do minimal damage to your structures even on Hard, unless you somehow pop dozens of Junk objects on the map on a single Wave.
  
  
• Don't be afraid to sell structures. You'll make up for the sunk cost easily since you're freeing up your Upkeep Tax, especially later in the game.

A common approach when looting Gleep Vats is to plonk down a Beam Emitter, since its DPS boundlessly (?) increases the longer it fires on the same target. However, I've worked out some math on how effective this actually is.

As an example, I attempted to loot a Gleep Vat not at a start of the run, but at Wave 5. The Gleep Vat broke at Wave 11. The waves had the following composition:


And that's excluding any rewards from rushing the wave and from clearing Junk. A Gleep Vat is worth 1,500 Cred, so placing a Beam Emitter down will net you: 1,500 - 48.12 - 35 (refund cost of Beam Emitter when sold) = 1,417 net Cred. And that's assuming:

• You sell the Beam Emitter immediately after breaking open the Gleep Vat.
  
• You don't rush any waves, or get any other form of income while breaking open the Gleep Vat. Note that extra income "inflates" Upkeep Tax.

My approaches when opening Vats are the following:

• Use a tower you're actually going to use for the map. If you're actually planning to use that Beam Emitter, and it fires 90% of the time (i.e. it's positioned in an active area of the map), and it clears important objectives (Brutes, Leviathans, etc.) for you, then you're set! Other decent choices include:
  
  • Ranger, Gatler turrets have usually global map range (save for line of sight) and can typically prove useful after disposing. The Level 1 Gatler in particular can dispose of Gleep Vats in a few belts (~5600 damage per full ammo belt).
    
  • Mini-You Fabricators are also effective here, since they have global use after popping the Gleep Vats.
• Ambient AoE damage, such as from Artillery and Ground Pounder turrets can damage obstacles, including Gleep Vats.
  
• Brian Jar with level 3 damage can solo a Gleep Vat in roughly 5 minutes. Way faster if you have an Artifact such as Enrage Brian on Hit.
  
• DO NOT do the Beam Emitter approach if you miss it in the early game. The income gets so high once you pass the early game (say ~1000 Cred per wave), the Upkeep Tax of an additional Beam Emitter (and the risk of you forgetting to sell it) is not recommended. Just hit Prioritize Target and let your existing towers in range help you out.

Chops to:

• AgedBlain for pointing out math errors!