Nice work! Love the characters and dialogue, I looked forward to the next cutscene each time. Love the details, too, like the medal around the “neck” of the submarine. I like games where the difficulty level is a little frustrating, but where the game keeps me playing, and this one did that. The gauges at the bottom for tracking your stats worked well and the depth damage worked smoothly, too. Amazing that you made it in 4 days.
The tilting hitbox definitely took some getting used to and was initially frustrating when trying to pass through two-block sized openings, e.g., but on repeat plays I got better at it and started using it to my advantage. The hitboxes on corals also felt a bit on the aggressive side in a way that made it hard for me to know how to maneuver between them (or fire a torpedo between them). I tried out the dash a few times but had a hard time controlling my movement and integrating it, so I ultimately played the game without it.
I made it all the way to the end (?), defeated the boss and got the notification to press E, but when I pressed it repeatedly, nothing happened. I beat it a second time, making sure I had all the feathers, same thing. I beat it a third time and this time tried to rush all the way back to the crane at surface level, thinking maybe I had to be there, but it was such a long way back to the opening out of the boss area that even with 15 seconds to spare after beating the boss, I never even made it back to the part where I could start ascending again. So at that point I called it a day, but it was fun for sure. Only wish I had seen the final dialogue (if there was one?). Nice work!