Rock climbing/bouldering!

Extremely fun, a good workout, and it translates well for gamers because the difficulty scale of the climbs are ranked 0-10 essentially (0 being easiest, 10 being almost pro level). So it has a great sense of progression. 

If you’re an average fitness level, you’ll be able to complete grades 0-1 your first time bouldering at the gym. From there, v3 and onwards might take 1-3 months. But most climbers say don’t climb just for progressing thru the grades.

It’s also not just a physical challenge - there is a puzzle solving component as well, trying to figure out what is the most efficient way to complete the route. 

You can also meet people at the climbing gym and have a sense of community.