I love how everything in this game is used. Not a single block isn't used. Not a single walkable tile is misplaced. And knowing there is no redundancy actually made planning a route slightly easier and using this knowledge was a great feeling. That knowledge led to the rather simple discovery of the Holy Grail ending which was well implemented.
The difficulty of this game comes not from the single screen puzzles but how each screen interacts and the further you progress into the game the further apart the screens that interact with each other are. The simple art allows you to focus on puzzle though I don't think better graphics would go astray.
This is truly a brilliantly made game that doesn't complicate too many mechanics. I highly recommend this puzzle game to anyone who can likes to think outside the box.