Awesome! Subnautica is probably an obvious influence. I really enjoy that game. The main aspects being strong atmosphere and the theme of an exotic, alien planet. Hopefully, I can find my own approach to those shared ideas.
Better controls or definitely a possibility. This was more or less a pretty basic example, so might not feel very aquatic, but if I continue development in a serious way, I'd want to revisit this. Can you tell me more specifically what you felt wasn't quite right about the sub controls as they are now?
Upgrades for the sub have been mentioned by more than a couple people already, so I think that's the favorite request at this point. I'm not sure yet what exactly I'd want to do with that, but I will definitely give it some serious thought.
Crafting hasn't been mentioned until now, but I could see that working into vehicle upgrades or even base building, and then we suddenly have Subnautica. haha So I'll definitely hesitate to do everything Subnautica does since I'm interested in doing my own thing, but at the same time, if I were to make Subnautica 1:1, it'd probably still turn out pretty differently since it'd be me making it. At least I'd like to think so.
Not sure if you are requesting that I turn it from 2.5D side scrolling to a fully 3D exploration space (again, like Subnautica) or if you meant something else by "3D update", but for now I think I'm a little more interested in 2.5D games at this time. I like how 2D spaces simplifies choices and puts an interesting design constraint on me but offering 3D visuals (and sound) provides a deeper artistic richness as a backdrop. Similar to an Ori game's visual depth without being truly fully 3D. Please let me know if there's more to what you were saying.
Would love a little more detail on the items above if you have another moment.
Thank you so much for playing and sharing your thoughts! Super helpful. (: