The background color is very beautiful!
I didn’t find any bugs, but it’s a bit strange when the character jumps. It feels that the character’s gravity will change when it leaves the ground (I guess it’s because of too much friction on the ground?)
This might not a problem that needs to be corrected, because it makes the role becoming difficult to controlling and it's challenging. It depends on you!
Every cloud looks the same. Maybe you can draw different shapes of clouds to make the scene look better.