https://youtu.be/jdnTmfOc3uY

Level 1 0:00
Level 2 3:22
Level 3 17:29

https://youtu.be/KPTPZBecffM

Level 3 Cont'd 0:00
Level 4 6:50
Level 5 17:15

Why chapter 5 is impossible

1. You fall through the floor when you stand on boxes.
2. The Crates NEVER stand still.
3. You lose health every time you reload until there is nothing left.

In my personal opinion I've played many games like this one where the developer will insist that there is nothing wrong with his/her product and that the fault lies with us gamer's not doing it properly. Truth is the developer probably did not expect anyone to get as far as they did and NEVER invented any levels or conclusion to their game. My suspicions is that level 5 is thus as far as a gamer can go. After all why would you not just simply fix your game if you in fact had a completely working one? It's because you don't.