It's like a fishing roguelite. Neat idea! I liked the variety of sprites for the different fish and I liked the cute images for the upgrades. My favorite was the one for the "Heavy Fish" showing the fish drooling over fast food. Those help add a little personality to the game.
Only improvements I can think to suggest is maybe more visual changes for upgrades. Like maybe you can see the fish silhouettes getting increasingly bigger, or a visual for how far you can fish, and it gets bigger when you upgrade it. This would help the upgrades feel more substantial.
I found myself getting really good at the timing of the fishing mini-game that it became maybe too easy. Perhaps the timing could be less forgiving on the heavier fish?
Seems like there was a bug on the 25 kg offering where I had fished 27.5 kg but it still said I failed? Unless I misread the number before the god showed up.
Overall, a nice idea and fun premise for a fishing game. Nice job!