I love the pixel art aesthetic, its really cute and charming. The music also suits it really well.
Some things to consider:
* I found the jumping to feel quite floaty which made it hard to get my character to do what I wanted it to. I think it could benefit from jump physics more akin to that of super meat boy, where the character begins falling as soon as the jump button is released (doesn't need to be that extreme but somewhere in between would be good)
* I feel like making the obstacles completely change each loop kinda defeats the point of it being a loop? Because it kinda ends up just playing like a regular endless runner. I think it could be more interesting if obstacles were gradually added, without removing the obstacles from the previous loop, allowing the player to use the skill built up from previous loops to traverse more complex obstacles.
I should note that I ended up making quite a similar game to yours, so I am definitely biased in that regard.