Clusters of colorful geometric shapes fall in sets of 4 from the top of the screen. The idea is to pair up matching shapes which then disappear from the playfield. Press left and right on the D-pad to direct the falling cluster, down to make it fall faster, or rotate it counterclockwise by pressing the B or C buttons. Chain reactions, needless to say, add up to big points. There are 7 different shapes: white squares, green squares, blue circles, yellow triangles, red inverted triangles, orange diamonds, and purple crosses. They're magically delicious!

   There are three ways to play: 1P and 2P, 1P vs 2P, and 1P vs Comp. 1P and 2P is a nonviolent competition to see who can amass the most points. You don't even need a second player, just don't press Start on controller 2 and you can enjoy a bout all by yourself. There are 4 different modes: Round Mode, Normal Mode, Doubt Mode, and Block Mode.

• Round Mode: This is sort of a puzzle mode consisting of 10 stages (0-9). Each round has a bunch of whirlybob ring shapes interspersed with other normal shapes. Just like the other shapes, the whirlybobs disappear when paired, but since whirlybobs don't fall from above, the only way to eliminate them from the playfield is to clear out the shapes between them in such a way that the whirlybobs touch when the structure collapses. The time limit is 3 minutes for each round, and keep in mind that pausing the game doesn't stop the clock, so you'd better remember to go before you start. If you've blown the round (ie, if you're stuck with only 1 whirlybob left), press A and C simultaneously to give up.
• Normal Mode: This is just the standard low-pressure game. Play for points as long as you like. The better you perform, the higher your level will rise. As you climb the ladder, the speed at which clusters fall increases.
• Doubt Mode: The rules are normal except that white squares will never fall. Instead, a random block from almost every cluster will turn into a white square when it hits the ground.
• Block Mode: This mode defies all Newtonian physics by having clusters stand on-end. Stack 'em up as high as you dare for massive chain reactions. It only takes a single pair to send the whole tower tumbling.

   1P vs 2P is where Sonic steps in to inject some violence into the proceedings. The rules are normal except that now you've got 10 minutes to either amass more points than your opponent or hope he screws up and fills his bin before then. In the middle of the screen stand a pair of Sonics back-to-back, sprite ripped straight out of Sonic 1. Create a combo and your Sonic avatar will attack your opponent's (by punching, kicking, spinning, or even a sparkling Muteki spin). The attacked Sonic will become momentarily dizzy, during which time the victimized player will have minimal control over falling clusters. In addition to all the basic shapes, players have additional "?" clusters to deal with: you can't see what the shapes are until they've landed, potentially destroying planned combos. You cannot pause in this mode.

   1P vs Comp is exactly the same as 1P vs 2P, except that you're playing against the computer. At the beginning, you can choose the difficulty setting from 0-9. The higher the level, the faster the clusters fall. Beat the AI to view the game's credits, a whopping crew of 4.