>>714764521
This doesn't give me an idea, but Nintendo isnt big on "bounty hunting mercs".

An online single player arcade rail shooter. Classic arcade games, a second player could join in at any time.

Make the game where you're on the call to track down a bounty. Everyone online gets the call, so it becomes a race of who can get it first.

You can play a run of the mill single player campaign, or you can race other star fox players to the bounty.