Challenging, but lacking a much needed autosave.
I started playing this at a time of afternoon when my brain probably wasn't up to the challenge and I didn't finish. But, alas, next time I play, I have to start from the very start. The first 3 puzzles were relatively simple, which I knocked over in about 5-10 minutes each, but the last one involving the 2 circles (not the overlapping ones) really bugged me. I would have liked to come back to it another time, perhaps when I was a tad more refreshed, but I can't, because of a conspicuously lacking save function. It's like trying to eat a massive dish, but every time you become full the meal regenerates. Overall however, the game was very entertaining, and the difficulty wasn't so impossible that I didn't get some satisfaction out of completeing them, as opposed to flinging my keyboard across the room. I think though, with a game like this, the seemingly minor design flaws undermine it quite a lot, and I think it would have been WAY better if I was able to try a puzzle another time when I wasn't feeling so tired and irritable.