Great concept ! There are just 2 things to improve in my opinion :
- There is a friction against the walls that means we have to stand back and away from the wall to be able to jump. That hurts the flow / speed of the run and is quite frustrating.
- Falling into the pits / area of red that we can't get out of (basically means the run is over) is too punishing I think.
Other than that, I think the idea is really good : collecting time in some parts of the level so we have time to explore others.
Aside from the problem with the walls already mentionned, the controls feels good and responsive. The audio is good (although I would tone down the jump / collect sound volume relatively to the music's just a bit) and the simplistic graphics also work I think.
Good work :)