If you have a nice system with a good video card, why would 900 fps be hard to believe? My laptop is ancient with no video card and it almost gets 200 fps. Of course the algo that figures the fps is a very basic one... increment the framecount until 1 second passes, so it may be a couple off here and there, but it can still be used to measure different peoples rates.
As for calling it Tetris, I cant really do that since someone already used that name!
Piles = piles of blocks, lol.
Thanks for checking it out and posting!