Honestly, for a first game jam this is some amazingly high quality stuff. Most first jammers tend to aim for scopes too large to be done reasonably well in the time given, but you kept to something small and fun so that you could polish it to a tee, and its 100% paid off so well. The music is so jazzy and fits the whole cozy skating so well, and the pixel art is stellar! (You even kept everything to the right scaling :D) Also the SFX of the skating is surprisingly nice too, like oooo it tickles my brain
If I were to find areas of improvement, it'd just be small minute things. For example, having a simple animation/alt sprite of a button being pressed down helps gives buttons some tactility (if thats the right word), so yknow they feel like actual buttons.
I guess another thing from an art perspective is that I'm not sure if the bird needs an outline, as the bright colours contrast really well with the darker orange background, so its already pretty visible! Adding the outline kinda makes it feel like its from a different game, as nothing else bar the title is outlined. Again, its a minor thing, so not something to worry about.
In the end I'd just love to see more of this! More levels, biomes, skateboard styles, a few animations of the bird doing tricks and such, etc. You've got a really nice chill game here thats really enjoyable, and I'd love to see you take it further!