Continuity mistake: When Captain opens the bridge gate he puts his right hand to his chest. From the opposite shot it's down.
Continuity mistake: Princess Dawn is in her chambers and her servants are preparing her for the coronation. When her book-headed valet tells her "You have come of age", he is suddenly holding the tome with both hands, while he had just one on it before the cut. (00:19:30)
Other mistake: After Kevin and Holly go kayaking in the ocean and get to shore, their upper bodies and hair are dry despite having been in a tandem-style sit-on-top kayak, which generally means the kayakers will get quite wet. (00:03:40)
Continuity mistake: Some figurines on Lidya's nightstand changed positions near the start. The rabbit was moved closer to the front, then back. The blue object was moved back a couple inches. (00:03:15 - 00:03:58)
Continuity mistake: In the first WW2 flashback the protagonist is handing the various items to the Nazi doorman. When he puts down the pen, he is doing it with a left hand in the table close-up, but he picked it with his right, as the left arm is busy holding the coat. (00:02:05)
Plot hole: *SPOILER* Calvin's twin sister and mother were killed years earlier in an automobile accident. Calvin kept going to his doctor with "new symptoms", insisting there was something physically wrong. Dr. Collins told Calvin, "Your health issues aren't physical. I thought sending you to that support group would give you a better perspective." The doctor should have referred Calvin to a psychiatrist for a diagnosis and, if appropriate, the psychiatrist would recommend therapy or a support group. (00:10:15)