The Bug: Trampolines only direct the player upwards, no matter what their orientation is. Even when put on their side, they still only project the player upwards.
The 90 degree bug can be used to create large upward lifts and sky elevators like seen in the video below. And it also prevents a trampoline pen from working properly, like you can see in the end of the video.
Video: https://youtu.be/7dmTRpdFZNM
Images (Hard to discern from these pictures. Video is better):
From bottom - http://steamcommunity.com/profiles/76561197984342374/screenshot/278472567125453304
From top - http://steamcommunity.com/profiles/76561197984342374/screenshot/278472567125453521
