I want to know if change falling speed is possible?

Currently it's not, and we haven't planned to make it customizable. The main reason is that Flash handles fast speeds very poorly, and some mini-lags could cause big gaps in very high speed.

thanks for you're answer ^^

If you want a speed option, put it in the suggestions thread

Speed option was already suggested.

But still, current speed is really slow. After introducing an editor things would be even worse: we'll get a really hard songs which are impossible on default speed. At least we need something to toggle our current speed bonus as permanent (which was suggested too).

Melibellule a dit :

The main reason is that Flash handles fast speeds very poorly, and some mini-lags could cause big gaps in very high speed.

Until this lags do not interfere with gameplay, just assume our gamers playing top-notch pc's. But, I still believe, there is a plenty of ways for optimization.

Seems that this has been answered, locking. =)