WalkScape: Grind by walking!:About

From The Walkscape Walkthrough

WalkScape is a game inspired by classic point-and-click MMOs but with a twist - you progress in it by walking in the real world! It's designed to be non-intrusive, with no predatory monetization practices. By non-intrusive I mean that it will truly let you enjoy your time outside by not constantly requiring your attention. Everything that needs active involvement (like combat or quests) should be done when you get home. The main goal of the game is to make people more interested in walking by giving them an amazing gaming experience to motivate them to keep walking. And you can play it while at work, or when you are walking with friends, and while walking your dog. You can truly focus on what you are doing and do more active playing later.

The game already has plenty of skills to progress in, and more are planned. There will also be a combat system in the game that requires active playing but is completely optional. You can play the game the way you want, like just collecting items and crafting things. Maybe even selling them to other players.