Acid Knife is a running, jumping and fighting game where you carefully time attacks to defeat monsters in a dark, psychedelic world. All of your abilities, such as attacking and dodging, are tied to the items you hold which can be knocked from your hand at a moment's notice. The balance of intentionally targeting enemys' weak spots and the need for improvisation when things go awry makes for a uniquely challenging game.

You play a small creature in a hellish, dark landscape that seems to shift and writhe as you move, and must face hideous, horrific monsters, like rotting, undead spiders and flying, bony, serpentine apparitions. To kill them, you hit them in their weak spots, highlighted by glowing red areas, with arrows and knives while simultaneously dodging and avoiding their attacks.

As you progress you learn that each of your actions, such as blocking, dodging, eating and attacking, are governed by items you hold: axes, knives, potions or even instruments. These can be knocked out of your hand by your opponents which forces you to improvise and think up a new strategy on the fly as you try to recover your item.

The result is a unique blend of careful movement and attacks with quick thinking and flexibility as you continually adapt to each new situation you find yourself in, creating a novel and engaging game.