I liked the interpretation of the concept! I think if you'd want to improve on this you could implement a visual feedback for the player to know when their R is working! Just some clock going backwards appearing could do the trick. I couldn't make it past the ditch either but now I get it so I am going to go back and try it again! 

The sound was really nice and calming, the visuals were simple but very good nonetheless. In regards to the R being a bit slow - as I was playing I thought of a little solution that may work better - and that would be trying to track the objects movement in real time through a variable and then when the player presses R you only target the movement variable to go backwards in time! But that's just a guess!
All in all good puzzles - totally worthwhile- 

I liked the music, simple but enjoyable. I liked the concept of the game. It was a neat idea but flawed.

I got stuck on the fourth(?) screen, the one where you had to climb back out of the pit.

I thought I was coming close to a solution but then I’d get stuck again and the reversing mechanic seemed inconsistent at best. Took me awhile to even figure out what could be reversed.

Also, everything also had a very floaty feeling to it which made things hard to control.

Overall, not bad for your first game.

Keep it up!