Thank you, I'm so glad that you think the game played smooth, and I'm glad I was able to achieve an underwater feel for the game, that's music to my ears! :D
As for the graphics, that's a big thanks to the rest of the team, they done amazing on the 3D modelling, and I think them making models for this game has made them more confident with making models in general, which I couldn't be happier with!
For clearer models, I think that is completely down to the resolution to get the 'retro' vibe, I think if the resolution was any higher than what I set it as, it would lose the vibe, if you want to see some of the models in more details, ask my team for pictures and I'm sure they will happily send them your way.
As for the controls! The lack of use for the barrel rolls and somersaulting, that was all down to me not having enough time to implement any more gameplay mechanics into the game, as I finished this with just over 14 hours, being the only programmer on the team has certainly made me realise that I like solo-ing the programming part of the development, but it may have been helpful to have an extra hand.