Mono gameplay:

Hit colors. Dodge greys.

Midway 4

Four lanes.
Never hit a grey to get a stealth bonus.
Fill the grid before the big Power Pellet spheres to turn blocks into Power Blocks for longer time.
Greys stay in the grid for a few moments, and may prevent matches being collected. They stay longer the higher they are.
Bonus points are awarded for largest match during the song.