I did see the "Press Space" message, but it did not stand out where it was, so the game had already generated an impossible maze by the time I noticed. I did read the game's description first, so if you had said it there as well, or maybe in a more prominent a message after the start screen, I probably would have seen it.
I think the game could be okay without music, but having an 8-bit sound play every time the player moves and a second "get" sound when you get the coin would add to the atmosphere.
In all, a cool unique game.