Good ideas !
The ambiance is good thanks to the music and all the other stuff (well, don't know what else to say, i got into it) ! 5/5
The idea of the world changing according to luck is very good, yet i think you could do more, like changing the background or the music... That's why 4,5/5
And maybe the inertia is not well adjusted (i died a lot trying to cross an edge...) and difficulty could be improved, but, yeah, that's a demo ! 4,5/5 for now !
So, keep at it !