The iPhone app, which is free, gives you three different Mugen Pop Pop play modes: normal, repeat and scramble.
Normal - Touch Mugen Pop Pop bubble to hear "Pop" sounds - Be on the lookout for surprise sound effects!
Repeat - Select difficulty level - Mugen Pop Pop will play a "Popping" sequence and then flash all buttons. It is then your turn to "Repeat" the popping sequence. A sound will be heard when you've completed it correctly and new sequence will start.
Scramble - Select difficulty level - Mugen Pop Pop will illuminate one or multiple "Pops", you must "Scramble" quickly to touch the Pop before Mugen Pop Pop scrambles you.
Get a poppin'! [iTunes]