Continuity mistake: When the door to Shrek's house is first opened (just after the honeymoon), it opens into the house. Every other time it opens to the outside. It's not a two-way door, because you can hear it hit the doorframe. (00:04:50)
Suggested correction: How is that a mistake? Lots of doors open both ways.
Doors that open both ways are called a double swinging door and use sprung hinges (or gravity) to bring it back to the center/closed position when not being pushed. It can go both ways because there is no stop casing for the door to hit against when closed (or frame is that is the design). We see Shrek's door hit a stop when slammed, and hear it hit the stop. Meaning there IS a stop, so it is impossible for the door to swing past it, meaning it is impossible to be a double swing, but we see it go in and out in different shots, which would be impossible.
Plot hole: It is apparent that Shrek and Donkey have never traveled to the land of Far Far Away, yet Donkey immediately recognizes the "old Keeblers' place" when he should have no idea where it is or what it looks like.
Suggested correction: Donkey only thinks it's the "old Keebler's place." Puss in Boots then corrects him and says it's the Fairy Godmother's cottage.
Continuity mistake: When Shrek and co. arrive, as the coach travels down the drive way you can see the door handle. The servant opens it. When donkey says 'I'm going to park the cart...' he jumps in and as it passes Shrek at the back, the handle is gone.
Suggested correction: Handle is always in place.