Terminapor - that is seriously awesome. It's exactly like the original! Even better, it runs smoother! (well except for some small slowdowns, probably caused by the recording?)
I love Rayfan's idea of upgrading the graphics, and I also have a few suggestions that don't involve changing the graphics:
1. Try making it widescreen (including an option to just change the resolution so when someone wants to upgrade the graphics he'll be able to)

2. Add a changeable tone/pitch to the ting sound like in the Playstation version
3. Make Rayman crouch differently depending on the angle of the platform he's on, like in the Saturn version, and maybe make the vertical position of Rayman's feet change depending on the angle of the platform he's walking on as well.
4. Add stuff from the Rayman 2 2D Prototype.
5. Add more worlds, more effects, more enemies. The enemies you made look gorgeous so far, better than any of the enemies already in R1 actually. Creativity ftw!
6. Port to all kinds of platforms
7. ???
8. Profit!
Anyway, it's awesome already - hats off to you!