Solid game!
First, the character is not in water. Bonus points for that xD.
Now, for the real review ^^. The controls are sharp, and the fact that we can move horizontally while ground-pounding is a really nice addition. I wasn't expecting it, and it made it really fun to break through multiple platforms at once!
The level design was pretty good, but it felt sometimes unfair to lose a life because of a red enemy that was off-screen before the pound, and that I couldn't avoid. Maybe if I could cancel the ground-pound to fall slower and avoid them, it would feel less unfair?
The music was punchy and catchy, but I would have enjoyed more sounds, especially when crushing a platform or squashing an enemy. It would have been even more satisfying this way, but I enjoy the little "squashed" effect =p.
The ending was hilarious xD. The cutscene is really good and is a perfect finale for suck a goofy character!
So yeah, overall, I really liked this game. It's simple, but with a clever mecanic that makes it really fun ^^!
Oh, and be careful, when the game starts, it's possible to press "left" and ground-pound at the right time to go above the left wall and escape the level =p