Continuity mistake: In 4th black's move, king's bishop go to third row (A3) and capture the white knight. There is not elipsis yet, but. in 6th black's move, Geri's imaginary opponent takes a piece from A4 to B3 and capture a white pawn. but there wasn't any piece previously on A4, in fact, pawn was not moved before, staying on B2, its original place. In the next shot black bishop remains on A3 and white pawn on B2, as nothing was happened.
Deliberate mistake: Throughout the whole short film, Geri's hair doesn't move or react to anything (such as the wind or his glasses). The glasses even seem to go through his hair without any movement in his hair. (00:01:00 - 00:03:35)