I downloaded Bounce yesterday and have played it twice. Once alone and once with buddies watching. When I showed it to my buddies, their first comments were "Oh... it stutters a bit".

The game does stutter, especially in the beginning. It sort of freezes alltogether for a second and then continues. Frame rate seems very good though when it's not stuttering.

Controls are very responsive and it's an awesome demo to show off the device with. It's not really a game, since you can complete the first level in less than a minute and there are only two levels.

But to answer your question: Yes it stutters. It doesn't lag, because to me that means it's falling behind all the time and 95% of the game runs perfectly smooth.