The seagull is great!! I'd love to see him animated, maybe when the player jumps he flaps his wings and goes into a flying motion? Also I really appreciate how you used both the score and the health mechanics of the UI. There's a lot of potential style-wise here, like the cars being moving audio sources, platform textures, background art, and maybe the coins are actually like little pieces of garbage, like seagulls like to collect. Super great so far!