Just use the mouse! The standard rules of chess apply, and anything extra will more or less be explained. Just don't expect to keep track of everything.. NOTICE FOR CHESS NERDS: This game does not currently feature castling, promotion, or en passant! Some/all of these features may be added in future updates, but really, do you need to take this game so seriously? FOR ONLINE PLAY: Press '1' to enable markings on the board, and share your screen to allow communicating moves. It's not perfect, but it should be playable.
Credits are available in-game. P.S. I recommend either the Wizard or Shop Keep for a first time player! They offer the most fun options.