Deleting game data seems extreme, but that works, aha.
Clicking, I won't be doing that but at least someone else can use that advice.
Walk speed. Yeah it needs to be higher base at the start then, watching them walk around for ages at the start when you've got what 5 mins at most before people make up their mind about a game.
The game will not continue because that's not how browsers work. The moment it's in another tab, etc, it stops running. You need to add code to quickly simulate what would have happened and award it when the user comes back.