#StrontiumDog would work as an #ActionRPG. It would be best not to adapt any particular storyline - instead, write a new story, but with side-missions where Johnny hunts down various bounties. Maybe it could be squad- or party-based so the player can also recruit Wulf, Gronk, Middenface, Durham Red, Maeve the Many-Armed, Spud Murphy... heck, since 2000AD games tend to be in their own continuities, might as well give us Feral Jackson.
(Yes, I think Feral was a decent character)