Other mistake: Infiltrating the Airship: In the RBH/RPE route, when Henry uses the Rocket Jump to get onto the platform and follows Reginald, his legs clip through the railing as he rushes through the doors.
Other mistake: Infiltrating the Airship: At the start, click "Cannon Ball," then click "Chair." When Henry takes off in the cannon ball and crashes through the doors, for a split second, one can see that the doors are still intact after he breaks through them.
Other mistake: In the 'Valiant Hero' ending to 'Completing the Mission', Charles is killed when the space station he is in explodes. Somehow, his headphones survive the explosion that the space station and Charles himself didn't (they are found on his grave at the end).
Suggested correction: Who's to say that the headphones on the grave wasn't a copy or a similar one of the one he was wearing? We never see anyone return to where the ship exploded, so we don't know anything, hence it can not be considered a mistake.
Other mistake: Escaping the Prison: At the start, click "File," then click "Window." When Henry uses the file to cut out one of the window bars, he climbs through the window, and his head clips through the bars.
Other mistake: Fleeing the Complex: At the start, click "Charge Tackle" and wait for the timer to run out. The fail text says, "Notice that timer? Now you know exactly how much time you have before your terrible reflexes are revealed." This is because in the original versions of the Henry Stickmin games, the timer was only introduced in Fleeing the Complex. However, the timer has been added to all the new versions of the games, so the fail text doesn't make any sense here.
