I just tried again and that's miles better! Definitely looks like it's playing at the intended speed now.
The gameplay is fun. I'm not usually a huge fan of endless runners, but this one has a nice feel to it, and the bobbing of your Cetacean is a nice little attention to detail, as well as the high score being rendered in 3D space in the main menu.
If I were to critique anything, I might echo similar comments about depth perception feeling a little weird, but I think that just comes with the style of the game. Maybe a little tracer flowing out from the player showing where you are facing might help. Some more obstacles or moving entities would also be fun.
Overall, cool entry! Thanks for posting this. Coding graphics 'from scratch' is a huge pain and I appreciate how much work it probably took to get working.