Fun! props for coming up with a really cool and unique platformer concept. I think this has a lot of potential. I think the next thing it needs are checkpoints. Because dying and losing all of your pearls really sucks if you have to go back to the beginning. Plus it would give the gameplay some direction like "this is your next goal". That said I didn't get too far, I kept running out of swimming energy as the current stream part. So I'm not going to be too critical of that. Maybe there's a bucket to drop your pearls in later on that I didn't end up seeing.
I also notice that when you jump/swim the scallop usually ends up floating upside down? And then when you land, it flips back around which seems a little weird.
I think it has a lot of potential though, I'll keep an eye on the progress!