Solid game. Puzzles felt challenging enough and even thought it sometimes seemed hopeless, I could always find a way to make stuff work. Never needed to backtrack a large amount.
Very nice game. Around 80% of the way to completion I had no idea where to go, but the comments made me persevere (the answer was down 2 blocks of air). The Holy Grail ending reasonably easy to find and satisfying.
You can cheese the puzzle by having a block in the middle of the 3 block gap, pushing another block on top of it, reorienting your submarine and pushing the block the rest of the way to the button. Doesn't use top right or top left areas at all. Though I did enjoy solving it normally.
