Qube

P to Pause and M to toggle sound.

LEFT and RIGHT arrow keys (or A/D) to move around the field, DOWN key (or SPACE) to drop the cubes.

Pop all of the required cubes to progress to the next difficulty level (of 12).

Three cubes (or more) touching each other will pop, if you pop a bomb in that group it will take out either a horizontal or vertical line.

(Try going through the ingame tutorial for more)