I thought there might be a few skills you could add to the game to make it more fun to let you do more. Its OK if its really hard to work them up. But an example would be... time management skill (shaves time off activities you do. Like level 1 saves you 5% off time used doing something then tack on 1% saved for every x levels). There could be other skills too. Do you intend to add more monsters or magic to this game? You could add fishing for npc slave/helpers as a job; that's 1 skill. I don't yet know if you've added farming skills to the game but I noticed you can buy a ranch later so maybe you already have that(?).
You could add more merchant quests and merchant storyline to the game also. Like XP or money earned for doing travel contracts and bring items to different shops in various places of the maps. Like kill quests only instead of kills make stuff. And merchant levels and make merchant skills into skills you can acquire also. You could add several merchant skills... 1 for discounts, 1 for upselling or marketing, etc.
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You don't technically have to add this. Your game is already good. But its fun to keep doing things and keep seeing what you'll add.