If this game was made like two years later it would have been much better.

A good idea with weak execution, mostly in part due to the poor physics. Jumping is almost fun but it just doesn't get along with the game. Collisions can also be wonky.

The biggest sin is multiplayer is worthless since you'll just be unintentionally working against each other despite it being co-op, which (while not this game's fault) goes against everything Nana and Popo are known for these days.

Also visual level variety would have been great.