To guys complaining about level 8. This level doesn't require pixel-perfect placing. Just think a little and you will find another solution that is quite easy :)
P.S. The same about level 16 - it doesn't require any perfect timing - just think a little how you can forbid the green elevator touching the red button ;)
The bug with none-existing bonus levels 4, 5, 6... is fixed. The new version is uploaded. (You may need to clear browser caches so see the fixed version)
2mightyshadow: Thank you for founding that bug. I removed next-level button for the bonus levels but I forgot that space can be used for switching to the next level :)
I will upload the fixed version when I fix that bug.