Low RAM usage, great visual style and gameplay to boot!
My only real gripe would be the controls. Even though the controls are listed upload page, it assumes the player is familiar with X and Z as inputs (if using keyboard) in the menu and in game.
Maybe using the ENTER key would be better as one of the buttons, to help users navigate the menu?
It would be nice if the use of the theme is a lot more prominent in the game itself.
Other than those 2 points, I really enjoyed the game!