Crazy to see a custom engine, well done for all that work!
Sadly, I wasn't able to complete the loop (couldn't find my way, maybe you should add red objects like Mirror's Edge) and had difficulty with jumps (because of qwirky collisions, like on the stairs I was literally flying?).
The art is cool, maybe a bit "burned".
I am a bit disappointed to not been able to experiment the loop, but congrats for the amazing work!