My boys enjoy playing lawn mower games online. There are several places where you can play these free games online.
I don't know why the lawn mower games are such a draw for them, but they have challenged themselves to keep getting to the next level.
When they are old enough to help mow the lawn, I don't know if their experience from playing these games will be an asset or not!
Maybe they will be a little bit more aware of the obstacles they could run in to, but hopefully they will not look at using the lawn mower as a game.