Nintendo has been doing a really great job of continuing support for the Arms with free updates since the game launched earlier this year. Update 4.1, which is available today, continues that trend by adding another new fighter without any fanfare. Yep, just a surprise drop of a new free character.
A new playable character enters the ring!
He's the ultimate fighting machine, the titan of tech, the tester of mettle...
— Nintendo AU NZ (@NintendoAUNZ) November 30, 2017
Springtron seems to be a robotic version of the box art character Spring Man. Originally available as a secret boss in single player, his electrified fists are not available to play with.
Arms has been doing a really good job of keeping itself relevant long term. You might even say... Arms has legs.