I hit level 5 first try. Couldn't beat that in the next two efforts, although I had some lag at a very inopportune moment - too many tabs open in my browser, I guess. I think if I played any longer I'd get a headache, so there's absolutely no way I can go after my 900-ish lines record (in regular tetris).
Seems like a good spatial reasoning/awareness exercise
As for VVVVVV, I played it yesterday. Interesting idea, but the implementation is too sadistic for me - I'm no masochist.