SubTerrania on the Genesis is one of those games that looks simple at first—just a little ship flying through caves—but man, does it get intense fast. You're basically a space delivery guy stuck in these twisting underground tunnels, dodging alien critters and trying not to crash into walls (which happens a lot at first). The gravity physics feel heavy, like you're constantly fighting to stay airborne, and those tight corridors don’t leave much room for mistakes.

What really hooked me was how it mixes exploration with panic—you’ve got to rescue hostages before time runs out, but half the time you’re scrambling to find fuel or avoid some weird floating enemy that shoots way too fast. The music’s got this eerie synth vibe that makes the whole thing feel even more tense. Not gonna lie, it’s tough, but there’s something satisfying about finally nailing a tricky section after wiping out five times first.

If you’re into retro games that don’t hold your hand, this one’s a hidden gem. Just maybe keep a walkthrough handy for the later levels.