Our new word game Wonderfall uses Bullet for rigid body ipad 2 case leather
physics of the letters against each other and the arena walls.
A free lite version can be found here:iPad2case
The collision results are excellent. The main problem we had was performance. The game runs at 60 FPS, but with approximately 25 letters on screen in an active state on a iPhone 3G or iPod 2nd gen it would drop to 30 FPS, since Bullet was taking about 8ms (half the frame time!) to handle the simulation. That was iPad2 cases
with all the tweaks I could find on these forums. On iPhone 4 or iPod 3rd gen, with their faster CPUs and graphics, it stays at 60 FPS in the worst case. Not a big deal in our case, since the bog happens when you are almost out of space and it just gives the player a little extra time to think.
Good job Bullet team! We are using it in our next project(s) and look forward to any new versions.
I have downloaded this game and set up in my Iphone.