First impression: strong OG Pokémon vibes, which is great. Cool that it's playable on a Gameboy. This has a good style and it seems there's quite a bit to explore. Here's my feedback after playing for about half an hour.
Text: I wouldn't move the text box up and down for each new line of text, only at the start and end of dialog. It's a bit easier on the eyes that way. The amount of text shown at a time is also not a lot, which makes it harder to read a full sentence, I think the font could be smaller so sentences aren't broken up into three or four parts. It could also help to only start a new sentence at the top (meaning, don't make the last of those three visible lines the start of a new sentence).
Tutorial: it's a lot of text. I'd much prefer a sort of trial run as a tutorial, the kind where I do immediately get to play the game but the game takes me through the steps by highlighting the right elements. The arrows you use do this just fine, but the text still makes it feel too much like reading a manual right now. Try to limit the text down to the absolute bare necessities. A line like "You can talk to this NPC over there" could easily be cut, because the arrow hovering over the NPC already tells me where to go. Something like the save station that "clones your DNA" is really funny and clever, but an animation could explain this too instead of stating it through text. Basically, try using visuals as much as possible to show/explain things.
I'd also cut the tutorial up into smaller sections and sprinkle them throughout the game itself. In Pokémon, you're not immediately told how to battle, gain XP, take on gym leaders, etc. after all. Firstly, you're simply told to visit Prof Oak, so the player gets to learn how to navigate the world and interact with NPCs. Then, you're taken through your first battle. At the first gym, an NPC tells you about those. Etc. I'd incorporate much smaller, gameplay-focused tutorials like that for your game as well. Make your tutorials as much as possible a part of the game itself.
Music: the ship music is great, I ended up enjoying that tune a lot. The shipyard tune on the other hand sounds too chaotic and random to play for that long, I'd probably prefer something more chill to listen to while I'm going around shops and talking to NPCs. The music in the area that had lots of greenery and tumbleweeds was okay, but also had a beat that felt a bit too random.
Lastly, some random additions: are you limited in color use? If not, giving each area its own distinct feel with color would make them stand out more from one another. Storywise, I felt a lack of motivation for paying my debt, because it didn't feel like my debt all that much. How about a short intro that has the player crash or otherwise cause something that causes a debt? Just a thought. The flying minigame had slightly jagged controls, sometimes shooting upwards at high speed, sometimes lagging a bit, but it was otherwise a welcome bit of variation in gameplay. The controls for walking and interacting are good. I liked the NPCs I came across and enjoy the ability to pick different crewmates as co-pilot.
Anyway, this ended up being an essay, hope you can use some of that feedback. Very promising game!