Pretty good. Some of the levels are quite clever. Others need a little work (like level 7, where you can just drop your items away from the placed ones, and the level solves itself...).
How does this game get a ranking below 3 (so far)?? OK, perhaps some of the levels are a bit too "constructed" in a way so that you can solve it, but just because it seems obvious - not because you need to think too much about it. But all in all, once you get the different blocks and their functions it's just a lot of fun!
Aaarrghh! I'm missing a single piece to complete level 7:6, with lasers going into every ship tunnel! I have moved items around for an hour and I'm almost ready to pay for that last piece...!!
I believe so... it explains why nothing's working ;).