* ActorAllusion: This isn't the only time Creator/JayBaruchel plays a [[Film/ShesOutOfMyLeague character that ends]] [[WesternAnimation/HowToTrainYourDragon his respective movie by flying away]].
* DawsonCasting: The 28-year old Jay Baruchel as the 20-year old Dave.
** Becky is played by Teresa Palmer, an Australian. Averted with Peyton Roi List, who is American.
** Jay Baruchel is Canadian. Averted with Jake Cherry, who is American.
* ShownTheirWork: As revealed in the behind-the-scenes material, the place where Dave has his secret lab (which is then turned into his apprentice training ground with Balthasar) is [[SinisterSubway an old subway turnaround]], and based explicitly (in architecture and design) on the City Hall IRT station.
* WhatCouldHaveBeen: An earlier draft included an appearance by Chernabog himself in the climactic battle, though he'll be in the sequel [[DevelopmentHell if they get the chance]].