The touchy movement appears when you repeatedly hit a movement key instead of just holding the key down. I optimized for holding key down to have a fluid movement (no delay at the start of movement like i.e. in your Tetris). But it seems everybody is so used to this flash bug(?) that they keep hitting the buttons :(
good luck with finding a partner. have you heard of kongregate? might want to check them out if you haven't...
Thanks for the comment on the color scheme. I've altered it slightly to be less headache-inducing.