I really enjoyed this one. The hints are well-paced, the puzzles make sense, the implementation is sound, and there's lots to play around with.
The only bug I managed to find was a small one which produced a small amount of contradictory output, but it didn't spoil anything. The game did give me an unsolicited hint at one point, but that might have been because I'd just asked it for a few hints in succession, and to be honest I really did need it.
Would definitely recommend this game.