Hey man, I'm glad you enjoyed the atmosphere!
Actually to swim, you can't swim at the start while looking up because, you're already at the surface. You need to look down so that you can swim downwards. Hope this helps!
Viewing post in Beneath the Bite (Trijam 293) jam comments
Nah that's on me. After it would have been more obvious if you were not looking up from the start. I'm glad you had a great time!
For the chest, indeed, I'm not scaling it. The game is actually in 3D with 2D sprites so, you're actually getting closer to it. You just don't notice that it's 3D because the movement is very restrictive. You can only swim up and down.