By all rights a game that’s billed as an arcade game, a mathematical puzzle game and a rhythm game all in one probably ought to be a mess. Those don’t seem like things that should jive. That’s the cool thing about Σ12 (Sigma12) ($0.99) though: it makes it work. Those aren’t three separate parts vying for attention, they’re one entertaining whole.

It’s a lot simpler than it sounds, mind. Start with a cube made up of other, smaller cubes. Somewhere inside is a strand of DNA—sure, why not. You need to locate that DNA strand before the timer runs out, and you need to do it by clearing away the small cubes. It’s probably worth noting at this point that Sigma12 is not also a matching game.

No, you clear out the cubes by counting to twelve. Each has a number on its faces, something from one to five. Find any way to make twelve out of that, from twelve ones to two fives and a two, and those cubes clear away. That’s when the rhythm game comes into play. Each level has a pulsing beat, and you have to make your matches to that beat to get the really good scores.

So that’s three major pieces of the game, matched up with three ways to score: completion, accuracy and speed. Might want to pick two, at least to start. Three stars is a great goal, but clearing away most of the cube while staying on the beat and smashing the time limit? Not super likely.

On the flip side, it can occasionally be a touch too easy not to go for anything much. Sometimes you luck out and find your way straight to the strand. This moves the game along quicker, sure, but it’s quite the empty victory. Not just hollow, but worthless, too: you’ll be quick, but your completion percentage will suffer.

Moving the game along does have its advantages, though. As you push through the levels, you unlock special blocks that make the whole Sigma12 experience much more interesting. There are blocks that multiply or divide the total of what you have selected, blocks that act like bombs, all kind of exciting things. The levels also get bigger and bigger, until they really push the limits of what you can easily navigate with swipes.

The game provides a great sense of challenge aside from the rare easy victory, and it feels worthwhile to go back and try for higher scores and more stars when you do slip through at less than your best. If it’s not enough of a challenge on its own, you can eventually give Infinite mode a try.

Infinite mode is a curiosity—a reversal of the main game. Instead of beating the clock, you’re running it out as long as possible. Blocks get added to the cube at a pace that begins at leisurely and rolls up to frightening, and you’ve got to do your best to clear them away before they fill up. At the moment this mode seems a bit too prone to major slowdown and crashing, but there’s potential there if that gets fixed.

Sure, Sigma12 might be a bit messy. There are a couple glitches, and the individual parts don’t exactly build to a crescendo. They do work together surprisingly well, though. Sigma12 is an entertaining arcade game, one that will use both your talent for numbers and your impeccable sense of rhythm.