Unless otherwise indicated, these are by unknown internet authors.
[edit] 4. Junkyard
Mammaloid Climber
Tormenting the climber
[edit] 19. Back and Forth
Shoofle's scorpion walker
Nice engineering
[edit] 20. Unpossible
Most insane basket ever
Shoofle's ball-and-chain
[edit] 21. U-Turn
Astonishing! - Does not finish, but shows some interesting physics errors.
[edit] Outside levels
Not the intended solution