Kage (or "The Legend of Kage" if you're fancy) is one of those NES games that looks simple but kicks your butt if you're not careful. You play as this ninja dude who jumps way higher than physics should allow, slashing through waves of enemies with a sword or chucking shuriken when they're just out of reach.

The first level throws you right into a forest at night—moonlight, cherry blossoms, the whole vibe—and suddenly you're getting swarmed by guys in black pajamas. The controls take a second to click (why does jumping feel so floaty?), but once you get the rhythm of slicing and dodging, it's weirdly satisfying. Just don't expect to beat it in one sitting—those later levels get brutal.

Also, the music slaps harder than your ninja's sword. You'll hum it for days.