I was determined to finish the whole game and it was definitely worth it. Fantastic concept, fantastically executed. Very clever (and tough) puzzles.
I really liked the way you introduced only a handful of different things (regular block, "charged" blocks, turrets, non-moveable blocks, spikes and a button) and did crazy things with those.
Also, there was some cool little details (like two missing pieces of floor in the last level) that were making levels a little bit harder and more interesting.
Great idea, great execution, great art and music. Really great stuff.