Nice job,this is a neat little game and I like the concept. The art is cool (especially the increasingly huge wings lol), the story is a little light but y'know, when you're a flying fish who cares about the lore?
I will say, the final wing upgrade is such a huge boon, it can basically solo the full run once you buy it. Unfortunately, the first wing upgrades are so underwhelming compared to the boots that I put the wings off until much later than I should have, and I got to ~25k with the boots (and level 2 wings) few times which was... a slog. I feel like the wings and the goal should be rebalanced, but I dunno
Alsohe sword hitbox seems to be mostly to the left of the character, which is a little bothersome sometimes when the enemies are approaching from the right, it seems harder to time the swing. But maybe that's just me
Overall it definitely did feel like a mid-2000s flash game, I can see learn to fly influences here. Though I agree it reminds me a lot more of doodle jump