It had a nice aesthetic but really needed some environment variety, ambient noise, and more mechanics than just picking up coins and jumping.
Also your sprite should be a little animated when running and jumping. Just sliding around makes it feel very.... Flash'ish.
need some kind of pixel detector.
50% Detector with short range only (2x the visible area)
75% medium range
90% long range
95% whole game field (to be able to complete the game)
Some Christmas music would definitely help! I got a little lost trying to find the rest of the yellow pixels.
lovely,i think you need BGM