I don't know about an 11th floor you're talking about, there's only 10 floors. Two of the floors are mislabelled. The controls are listed on the game's page, the browser version likely doesn't support controllers, hence why I recommend playing in an emulator like BGB. You can use healing items outside of battle, press Left Shift (For the browser version, or Select on GameBoy), it'll bring up a inventory menu. I'm aware of the mismatching magic in the skill selection menu, I'll get that fixed.
Thanks for playing.
EDIT: Fixed the Light/Dark equip problem and the level number error. Updated build is up.