great! this is really something. the first time I played it I didn't know about the panic button so, I got a little excited when I noticed the gravity and a little frustrated when the speed grew out of control even maintaining it's angle, position and velocity between levels. that was still really fun though. upon reading the author comments however I first thought "it's not a risk/reward mechanic if I have no way to control it and mitigate the risk, it's just mounting difficulty" then I kept reading, felt silly and went back to play again. very cool how you can click to slow it down, I also like that if you use it strategically you can actually control the ball a little in the air. I actually cleared the last 5 bricks of one level without letting it come down just by timing the slow down to get it to fall where I wanted (not the best way to wrack up score but it was fun and cool).
the only bad thing is, the window is kind of small and sometimes my mouse drifts out of it, which can easily cost a life/ball any time it happens. locking the mouse into the game window would make this pretty much a perfect game.