Hidden Back In Time level
To enter the hidden level in Back in Time, enter the Back In Time level door from the opposite side.
Hidden Autumn level
Go to the Autumn level hallway and go to the right to find a black wall. Double jump through the wall into a hidden hallway, and enter the door at the end of the hall.
Clock bonuses
Collect the clocks during the game to get bonus points. The points can be used to unlock the following bonuses.
Character Sketch (1 point)
Background Sketch (2 points)
Storyboard (2 points)
Backgrounds And Characters (1 point)
Behind The Scenes (2 points)
Intro Storyboard (3 points)
Hidden Autumn Level (3 points)
Hidden Past-Present Level (3 points)