Wow, really great vibe on this one. Lots of art to explore. I will try to give you some feedback for improvements...
- The startup is a bit slow, it could put you into the game quicker
- Instead of having separate E and Q to drop and pickup, maybe just E drops or picks up if there is one below you. This way the controls are a bit simpler. Also it could pick up regardless of whether you have that number selected.
- It should should you which sub you have selected
- The dialogue system looks really cool, I hope you get time to hook it up to gameplay.
- You can remove the text in the top corner by calling setShowWatermark(false)
Great start, I am looking forward to seeing how it progresses as you continue making improvements!