Bio Hazard Battle is one of those Genesis shooters that sticks with you—mostly because everything’s alive. You’re flying through these pulsating organic levels, blasting mutated creatures that look like they crawled out of a lab accident. The music’s got this weird, synth-heavy vibe that somehow makes the whole thing creepier.

It’s a two-player co-op, which is great because some of the later stages throw so much at you that having a buddy feels necessary. The weapons are fun to swap between—I kept going back to the homing shots, but the spread fire has its moments. Just don’t expect a walk in the park; this game’s got teeth.

If you’re into retro shooters with a gross-out sci-fi twist, this one’s a hidden gem.