Enjoyment: The jumping mechanic is fun! A little frustrating, but I think that's mainly due to the bug you mentioned.
Concept: I like the idea here, and would like to see it developed further. Feels like a good fit for mobile.
Presentation: It's simple, but clean, and with nice colour choices. I liked the quick restart, though a main menu would have been nice.
Use of the Limitation: I couldn't finish the level, but I'm prepared to believe there's only one.
Overall, good prototype, hope you'll continue it.