First off, timing didn't SEEM to matter. Not saying it didn't but I just pressed the arrows as fast as I could in the correct order and I won. I think timing is important.
Second, order isn't as intuitive as you might think. It took me several mistakes to realize when two options appear you have to do them left to right. I thought they were at the same time then thought you could do either or. If you want one done before the other they really should reflect that as they drop.
Lastly, While the avatars on the dance floor are cute and fun the arrows don't really take that into account. Maybe you should take damage if you press an arrow that runs you into another person, wall or enemy. That way when you drop two arrows at once I'm supposed to pick which direction I want my avatar to go for that beat.
This game has a lot of great potential!