I also loved this game.Simple and relaxing, if only slightly puzzling. I never had a level feel very challenging, which is fine in a simple sliding puzzle though I wouldn't mind some levels that really puzzled me. Note, that doesn't mean make the laser bars move annoyingly fast that isn't a puzzle it is luck. The game didn't really go out of the box anywhere. However where it did shine like a mofo was the soundtrack.. the soundtrack was so perfect. Often the background music is so bad in games like this I have to mute it. This was good. I very quickly found myself moving the cube to the tune. I am still listening to it. You, sir or madam, have made the perfect background track for your game.
If you didn't make the perfect background music you should give someone somewhere props.
As far as suggestions for this I think you have the basic elements of puzzle, one way doors, mazes, moving dangers. I think it is just finding new ways to trick us into making a bad move. I did, in the one level, accidently get trapped in the room with spikes and that was good you got me. If you run out of ideas with the elements you have adding keys, buttons, and portals (one or two way) is always an option. I am tempted to say I didn't care for the zooming... because I like to see the whole level.. But it also felt right where you used it... I guess I will go with ambivalent on that..
I do like that the game didn't feel like just another replica of other peoples games which can be hard when you are working in this kind of a genera. Some of the levels did feel similar to each other, but because of the increase in difficulty (the up down stairs levels with the lasers bouncing between the floor and ceiling) it was an acceptable repetition.
Overall great job especially for a first game!