Over the past couple of weeks, my immune system has been struggling to fight off a cold. It’s been unpleasant, as all colds are. But over the same period—in defiance of my plight—I’ve been waging my own war against immune systems, thanks to Pathogenic, a new roguelite twin-stick shooter from developer Aberrant Labs.

As I’ve downed endless shots of ineffective cough syrup, I’ve done little else with my free time than repeatedly take on the role of a bodily invader. And let me tell you: Being on the enemy’s side is much more fun. Really fun, as it turns out.

Action roguelites are a dime a dozen these days, and it takes something special to stand out. So as quiet Internet whispers turned into widespread cacophonous praise—the little indie game quickly racked up 100,000 sales and an “overwhelmingly positive” review score on Steam—I set aside my default skepticism and gave it a shot.

I’m glad I did.

Under the skin

A brief introductory video sets the scene: A hapless lab assistant drops a vial, and wouldn’t you know it, the poor guy has a cut on his ankle. That’s where you come in. As a lone pathogen, you work your way through his body, starting in the skin and then moving on to the intestines, liver, stomach, lungs, and finally heart. Each zone culminates in a boss fight, and you’re continually upgrading your build along the way to keep pace with the stages’ increasing difficulty. Defeat the dreaded heart to kill your host and claim victory (or forge on to the secret brain boss for extra bragging rights).