I played this for about 2 hours or so and beat 2 areas. I think I'll stop it there for a bit until I cover the other entries, but so far I'm really impressed. I really love the open-ended and metroidvania nature of this quest and the really cool ideas it has so far. I'll give more thorough details of it when I'm done but I'm liking how it's turned out.
Edit: On second thought, I probably won't have much time to finish this so I'll just say some more things here. In addition to things above, it's certainly quite difficult but well balanced. I never found a situation where things got too hard or too easy and despite no heart pickups, the save points were placed strategically and nicely scattered around the areas. When this quest gets a database release at some point, I'll definitely be sure to play through it fully. Nice job with this!
Btw I found a bug where you can happen to walk above the walls from the left when you get the flippers. Doubt this was intentional.
The bug shouldn't matter much anyways. I'm glad you enjoyed through what you have played through.
I saw the good and bad both ending, I had a good time. Thank you so much, a30502355.
You're welcome! Very glad you could finish the quest!