I took like 30 seconds to turn 180 degrees. However for looking on top and bottom it is faster and better. Maybe when you play it you don't have the same issue. I'm on mac maybe that's it ? But really I finished the game because overall that was a good experience and I loved the puzzles :)
Viewing post in Isolating Waters jam comments
I looked into the code in more detail and I realized I didn't make turning framerate-independant. Well.. I tried, but I didn't do it properly. I used a mix of Time.deltaTime and Time.fixedDeltaTime in Update(), when I should have only used deltaTime. That's why the turning was incredibly slow on anything less than 60fps. Even 60fps was slow since I tweaked the settings when using 144fps...
It's a pretty dumb mistake, but I already fixed it and will update the game when the voting period ends.