You kept the game nice and simple. However I feel like it is a bit to simple. It would be interesting to maybe have some blocks move sideways or maybe even have the player jump. I like the post processing effects on the border and the rainbow glow that it gives. However I do agree that the menu also is a bit lacking compared to the rest of the game. So give it a little UI update and some more interesting movement or something like collectables for a simple goal. Maybe take some inspiration from Run2Run2.