Solid game. :) Had some trouble with the fourth level in particular for a bit, tried upping mouse speed but realized it's actually better with a slower one, more precision... and if you take that route the last two levels in particular really aren't so difficult. Hardest bits for me were the timing/reaction-based sections.
Love the clean design, colorful, minimalistic and varied. Not too long either considering you go back to the start each time it's game over. Feels just right length and difficulty-wise. Good stuff.
-cd-