Deliberate mistake: In the opening title sequence, just after the title of the movie is shown, Puss cuts a P with his sabre into a curtain or flag. In the middle of the P, there is cloth remaining, but since he cuts edges all around this to make the Capital P, this cloth should fall away as it is no longer attached to anything, yet it floats in mid air.
Deliberate mistake: When C-3PO, R2-D2 and the younglings are driving through the battle zone, Anakin Skywalker and General Grevious can be seen battling. Later, Darth Vader can be seen on Hoth. This would be impossible due to Anakin Skywalker being Darth Vader. (00:08:50 - 00:12:20)