The Concept is superb. I should say that.
Moving on. I felt a lot of the puzzles were difficult. I'd sit here for 10 minutes trying to figure out some of the puzzles. I stopped playing at level 23 (so close to the end!) because of time problems.
In any case. The game is simple, it's fun, it's challenging, and the puzzles are very imaginative.
I like the style of drawing as well. Again, simple but it does the job.
I think one of my problems with the game is that it doesn't tell you which is what. It took me forever to figure out that the red blocks won't kill me.
Good game, nothing ground-breaking but worthy. 4/5