I know this is very incomplete due to no fault of your own, so I wish I could give more helpful feedback, but here's what I've got so far:
The controls feel nice and responsive, I like how the fish drags around the camera deadzone, it gives a feeling of movement even with a flat background
I hung around to watch the clock go past midnight and change days, so I can confirm that's fully functional, and I also like how you increment the minutes by thirty min intervals -- I might have to borrow that ;)
I tried build mode, but after I pressed R and the UI popped up, I couldn't figure out what to do next.
I read through your premise, and it sounds very fun! Excited to play more when it's more fully developed