Master Chess Multiplayer

good

Just the visuals are fine. However the AI is extremely weak (for some reason a common issue with flash chess games), but worse than that the game doesn't allow some moves or allows impossible ones to the AI's benefit. One time I could capture his queen with a bishop and the bishop could move anywhere but the square where the AI's queen was. On another one I delivered a discovered check and instead of covering or moving the king he captured a piece that wasn't checking which clearly isn't legit.

castling is not working as it should, the king shouldn't be able to pass a square where the opponent could make a move

Needs time control. Don't want to play when the guy is playing like it's classical

However you programmed en passant is really messed up. I did it and the computer made one of my knights disappear. He did not capture the knight, nor did any of his pieces actually move. Furthermore, I was able to capture into the square my knight was with a pawn, so the game thought there was an invisible enemy piece there.