Tap. Tap. Tap. Tap. Move. To. The. Beat. To. Beat. The. Beat. Second. Level. Is a. Little. Faster. Third level. Ramps up the. Speed so you. Got to keep. Moving now. Or you will. Die!

The rhythm game fad seemed to have passed us a few years ago as people retired their Rock Band plastic to the closet. Even before that, Dance Dance Revolution went by the wayside. Lately, however, we've seen a resurgence of rhythm games with the likes of Audiosurf allowing players to groove to their favorite MP3s and Theatrhythm letting us relive the glory days of Final Fantasy through the music. Crypt of the NecroDancer capitalizes on this concept with its quasi-turn-based, Spelunky-inspired roguelike adventure that charges Cadence, our heroine, to discover why she was sent forth into this undead labyrinth.

Like most roguelikes, the story isn't secondary or even tertiary — it's an afterthought to what's most important in roguelikes: the design. Ryan Clark, the founder and sole employee of Brace Yourself Games, has created something unique here. Several roguelike rules apply here, such as procedurally-generated dungeons, turn-taking, and hidden goodies to discover and then figure out. Unlike almost any game out there, though, the core of the game revolves around timed actions in accordance with the music.

In a sense, CotND is both turn-based and action-driven. Every enemy moves according to the beat of the music, with skeletons and blue slimes taking two beats to move, while a charging bull with a hand harp on his head taking a turn every beat until he rams into a wall. Cadence can sit still all she wants, but the enemies will continue to move. If she moves with the beat, her actions won't be interrupted by "missing" a beat, and she will maintain her gold multiplier, which is critical for shopping and earning a high score.

The controls couldn't be simpler — when not using items or abilities. Cadence moves in cardinal directions using the arrow keys and attacks by moving into an enemy. To use abilities, players have to press two arrow keys at the same time while still maintaining the beat; in this way, CotND mimics DDR. In fact, players can hook up dance pads and play the game that way, though I haven't explored this avenue.

Perhaps more important than the game design itself is the music. After all, since the gameplay hinges on landing beats, the music better be toe-tappingly engrossing. Simply put, the music haunts me. While playing CotND, I was bobbing my head and bouncing my leg up and down. When I walked away to make food, I was moving in time to the music I had just listened to. While listening to different music after closing the game, I was still moving in time to CotND's beats.

Which brings me to one of the coolest features of CotND: you can set up your own MP3s! Since CotND is still Early Access on Steam (but quite playable), uploading my own music took a few extra steps after some sleuthing on the game's web site, but once I got some Chrono Trigger tunes hooked up, I was groovin' to the opening theme, the battle theme, and Gato's song. After some brief loading time, each level I assigned an MP3 to found the correct beat and I had to move in accordance with the song I had chosen.

Although several pieces and parts (e.g. characters) are still missing from Crypt of the NecroDancer, the Early Access version can be purchased and enjoyed with confidence. Ryan Clark makes it clear when loading the game that much still needs to be done and may change, but what's here offers me assurance that the finished project will be one of the best indie games released this year or next. Until then, I. Will. Keep. Tap-. -ing. To. The. Beat!