Prey is an immersive sim meaning a lot of emphasis is placed on open-ended missions and level design, exploration for resources, and player freedom while surviving in the space station, Talos I. Through skill trees, you can spec in many different character builds that fits your gameplay style. Maybe you want to avoid enemies all together and be a sneaky hacker or have the many turrets and security bots fight for you after you repair them, maybe you want to face the enemies head on by focusing on guns and the leverage skill so you can hurl sofas and water coolers at them. The game caters to however you want to play, but no matter how you choose to build your character, there is always one common denominator: the GLOO Cannon is the most useful tool in your inventory.
The Gelifoam Lattice Organism Obstructor (GLOO) Cannon was not made to be a weapon; it’s a tool. It’s only through the ingenuity of the player character, Morgan Yu, that it has any use in a fight. The Cannon shoots out globs of foam that stick to surfaces, expanding and hardening into about basketball-sized clumps. Apparently these hardened clumps are called “splats,” but they look more like pieces of popcorn to me so that is how I will refer to them. This popcorn doesn’t do any damage to enemies on its own, but it does slow them down and completely immobilize them after enough has formed on them. The helpfulness of this cannot be overstated since all enemies in the game are extremely fast, zipping around rooms unbelievably quickly. If you do not slow these creatures down, they will quickly close in and take a bite out of you. The GLOO cannon is very useful to hold them in one place so you can go on the offensive. Luckily, besides just being slowed down, enemies encased in the GLOO take increased damage, especially from the wrench. You’ll quickly find yourself relying on a quick GLOO Cannon to wrench flowchart while fighting enemies—similar to the Electro Bolt to wrench combo in Bioshock and it’s just as satisfying here as in that game.
Again, though, the GLOO Cannon was never meant to be used as a weapon, it was designed as a tool and with that comes uses for it outside of combat. The first uses you’ll learn is to use the GLOO Cannon to take care of hazards around Talos I. Since the popcorn is nonconductive, it can be used to cover broken electrical panels shooting lightning out into the room. Once covered, you can repair the panel in order to stop the lightning if you specced into that build or simply walk past it and deal with it again when returning to the area. The popcorn is also flame retardant, so spray it on a burst of fire coming from a broken pipe and you can safely pass. These are all interesting little uses, but they are very situational. It aids exploration by reducing hazards, but GLOO Cannon’s real use outside of combat is how it lets the player access new areas.
The GLOO can be formed on any surface besides glass and is strong enough to even support the weight of a human being. This means that the Cannon can be used by the player to create climbable popcorn staircases to access out of reach areas or rooms that would typically need a much longer route to enter. You may discover this by accident, by missing an enemy and hitting a wall, but if not, the developers left a few examples of these stairs hanging off walls around Talos I. This technique reminds me so much of the wall jump from Super Metroid—it’s handled as a bonus use that helps you navigate the game world in not the obvious way, but players don’t actually ever need to use it to succeed and they may not even ever discover it. It all depends on how involved in the game you get—how far down the blackhole you fall.