"Syz: EG" is a slick game developed by TeamKrinoid using the Marmalade SDK that they have ported to the BlackBerry PlayBook recently. It has a really cool use of multi touch with each hand doing something different. You control where you are aiming your weapon with one finger while dodging enemy weapons with your other finger. This also means that the controls are not on screen blocking the gameplay. Syz also throws in some fun with different abilities and perspectives along with voiced dialogue.
Check out this demo of the game on the iPad to see what I mean: