Who isn't afraid of the bottom of the sea? Capcom Quest of Shinsekai: Into the Depths. Diving and exploring in a new IP.
I believe this game went unnoticed by many metroidvania fans.
Here we have a classic game where the focus is exploration and character improvement. You'll have to do both of these things to go deeper and deeper.
I liked the variety of enemies, but it's a shame that there are so few boss battles.
I recommend always leaving your flashlight on, it won't cost you anything and you'll be able to find places to dig and get items to improve your equipment.
As for the story, the game explains a bit in "art works" scattered throughout the maps. I didn't understand it very well, but it's probably to help you avoid an imminent threat.
And that's it, it's a new IP that was previously only available for Apple Arcade and is now also on the Switch. It's a very easy game...