In the game, you can (if you have any) invite a few Steam friends (no matchmaking otherwise) to fight an insect invasion through seven fairly extensive, but linear, levels that are unlocked with experience. Each level is broken down into several parts; finding an object (like explosives or a keycard) will open the next area. Checkpoint-only saves are somewhat frequent, and high scores are uploaded to the online leaderboard. Controls are typical (WASD to move, mouse to aim), although the angled movement through an isometric game worlds looks unnatural. Weapons are varied (assault rifle, shotgun, flamethrower, grenades, and melee weapons like axes and swords), all of which can be slowly upgraded (clip size, damage, firing rate) using money rewarded by killing enemies. Difficulty is achieved by spawning lots of enemies simultaneously; health pickups are infrequent enough where death is a possibility, especially on any difficulty setting above “easy”. Primal Fears features slightly annoying physics, as “sticky” collisions with objects can impede your progress. The insect AI, as you might expect, is very basic, charging straight towards you in almost all situations. In the end, Primal Fears lacks anything innovative for the swarm-based cooperative shooter.