Very nicely done! Great puzzle game. It is quite challenging, which in and of itself is not bad, although I recommend reducing the difficulty due to rock obstacles just a tad because it can be frustrating. For example, there was at least 1 puzzle where you had to separate your 2 energy sources horizontally by a certain distance to get them to move around rocks and reach the targets. However, if you created the wrong sized gap, or you accidentally created a vertical gap by bumping into one of the rocks, it was very hard, if not impossible, to correct, and you had to restart, even if you were on your way to solving the puzzle. Reducing this kind of difficulty due to frustration would help create a more enjoyable player experience. However, the bulk of this game is really well done, and I had a lot of fun.