Really good game! I found the concept and mechanics fun. Just two points of feedback: at first, I didn’t know I had to click on the tank to get oxygen until I read it in the description (maybe just a small “tap here” prompt at the beginning would help). I also felt that the difficulty scaling was a bit too easy—perhaps you could add a way to lose fish or to protect them, which would make it more challenging. But overall, I really liked it.