Pretty fun game concept, with the major twist on the whole "chill game about collecting things" trope. I think it could be taken to a cooler place in the future if you decide to revisit it!
For me, the seagull's movement is too slow, and the perspective too awkward in terms of being able to position yourself right for firefly catching, for the large number of fireflies and the short time limit. That's my main complaint, because otherwise, it's pretty solid, and the aesthetics of the game look great!
I really hope you do more with this some time from now, because this has a solid foundation to become a fun and humorous game that a lot of people will be interested in playing!