Boa now has an undo button!  Boa was the first proper puzzle game I released, and as such, it has some major flaws.  In particular, movement lacks smoothness and the difficulty curve is quite atrocious.  This update makes movement a little smoother (you can now move multiple tiles without having to release and re-press a key) and adds an undo button, which should help immensely.

As a side note, this game was coded extremely poorly, so this is the only one of my games where the stack that saves all of the moves (done via coordinates + whatever else can change during a move) is its own, completely separate object (normally I have each object store its own stack with its specific information).  This means I have to store slightly more information, though implementing it the other way would've required re-coding most of the game.