Can't remember the name of a game

[SarahJane12]

What's the name of this game? I can't remember the name of a game I used to play about 6 years ago. It was a puzzle style game that had different colored and different shaped monster heads (purple triangle, red octagon, blue squares, etc) stacked on top eachother in various patterns, and it had a pivoting grey "caterpilar" looking gun at the bottom center that you used to shoot matching corresponding monster faces at the puzzle. When you made the shot, they would "drop" sort of "tetris" style. Anyway, the faces would frown every now and then when you lined up a shot to shoot 'em down. Anyone know this one?