Nice concept very well produced; a good variety of puzzles too! Very smooth and entertaining!
My main suggestion would be that it needs a snap-to system; too many times I'd actually cracked the puzzle but due to a slight overlap it took longer than it should have!
Other than that a plot would have been good (the best puzzle games have variety in their puzzles and a bizarre plot, see 3 In Three), but that's hardly a must for a puzzle game! Brilliant stuff!
HOW TO CHEAT: There's a finite amount of moves for each block, remember? If you have trouble then start to go through them (up-down, left-right, backwards-forwards) for each block. Unless there's a slight overlap messing things up then eventually one will move significantly and you can move on from there! Also, the varied perspectives will help work out the block shapes.
EXTRA TIP: I can't recall any of the puzzles other than the last one* needing you to retrace your steps (i.e. get one block to a different position and then return all the others to the starting position); so long as you're not going backwards you're going forwards!
* Even then I'm not sure I took the fastest route!