NOTE: This post has a lot of mechanics / game design spoilers, but no story spoilers.
NOTE 2: This isn't me trying to prescribe what "good tactics design" is for everyone. I'm just trying to articulate my own personal tastes and rationales.
Horizon's Gate
Horizon's Gate is a retro pixel art open world sailing game about exploring towns and dungeons, buying low and selling high, and getting into battles where you push and pull and surround. It's very good and you should play it. If you don't have much time, you can probably stop after like 5 hours.