Fantastic! Great style, great idea. It'd be nice to have an in-game explanation of what A and B is, maybe on the bookshelves? The mouse sensitivity was a bit too high for me, but it isn't an action game so it doesn't really matter. The space you're confined to is small enough so you don't wander off looking for unnecessary things. The water divided-ness can be hard to read for chunks above 5. Overall, I love it.