Lovely physics puzzle game - quite cunningly thought out, and very playable.
Suitable backing music.
The first levels are basically a tutorial, but it does step up after that.
The one thing that annoys me, is that the help keeps coming up at the start of every level featuring a new element - but if you are replaying the level and already know what that element does, then it starts to bug you! Particularly since the help pops up a few seconds after the level starts, so you may already be in the middle of it and have already set things in motion! Please have it turn up at the very start, and to have the option to turn it off, particularly if replaying or reattempting a level.