The idea is really cool - and the atmosphere is really nice, the background sounds fit and make it kind of eerie, like a prison is supposed to be.
Overall, great work! Especially for your first game. Keep creating!
Here's some additional things I have noted:
- You could consider not centering the camera onto the player character at all times and confine the viewport within the boundaries of the scene. That way, you can avoid the black background for the most parts. I saw that you're using Unity - you can use Cinemachine Confiner 2D for this and set this up without writing a single line of code
- The Interact indicator when you're close to an interactable object is great. You could consider adding the actual button that the player needs to press though, something like "Press E to interact"
- I had a weird issue sometimes that the waterslime and ant sprites were backwards sometimes. Not a big problem - just something that I noticed
- I seemed to have a problem in the cake room - I did two playthroughs. In the first playthrough, everything worked and I was able to complete the game, but in the second playthrough I was not able to interact with the cake anymore...
- A WebGL game typically does not need a Quit button. When I clicked it, I had to reload the game
- The selection and usage of sound effects is where you really excelled - those are really good!