Updates to collapse

Hello! some months ago i uploaded Collapse, and now i made some updates:

- Fixed a bug where the players could softlock themselves by running to a big wall. Now if players stop by any reason, they die

- I think i fixed a bug that caused the player to clip the floor or ceiling on lag

- Moved the expert challenges from a DLC to something in-game

- Added a secret message for those who manage to beat level 3-3

Feel free to share your suggestions!