Thank you for playing! I appreciate the feedback, this will help me improve the game and help me make things fun for more players for sure! Level select is a great call out, interaction would be a good idea along with just making it more spacious in general. I have even toyed with the idea of making it a top down view more like Super Mario World or Shovel Knight and just make a Hub World map that opens up as you beat levels... I might get more serious about implementing that as well. I'll try some things and see what works.
I hear you about the design confusion, the Longnose Gar (fish) character was not intended to be a platform but rather just an enemy (they are a natural predator of crabs among other things) that players could ride on or use as platforms if they wanted to. I may set the collider so the player cannot stand on the fishes back in the future, it should not be necessary to complete any of the levels at this point. I got this note twice just here at the end so it does feel like something I should try to address. And the flipping is not a bad idea as well, I like the visual of the fish actually rotating around but gameplay is king for sure, I don't want it to make the game feel more frustrating and less fun.
Thank you for the Opacity fade out suggestion for enemy deaths though, I will start looking into that right away I think I could improve a few of my games with that feature. The instant removal can be a bit jarring. Plus I could probably use the same effect for the player during invulnerability frames... good idea for so many things!
I have run really short of time this week, and I don't think I managed to get to your game over the weekend but I saw the gameplay video was posted. I'll be sure to at least check that out and give a rating!
Thanks again and good luck with your game development!