this is litterally psych engine
When you collect basketballs during the fight, you can jump at their head and damage them
Sure! and for anyone else who plays in the future, i'll leave the hints:
Check the Data folder for a hint!
Click the hidden button!
Have you tried bending backwards?
Unlocked when you find all 3.
For as of now, theres only one ending, however, if you mean the last four glitch levels, they're all unlockable, but they're all hidden !! hope this helps
the man himself