Valve released a new game mode for Team Fortress 2 called Mann vs. Machine. The backstory is that you’re defending a base under attack by robots and you and a group of up to five other people must prevent a bomb from being moved to an end point by waves of server-controlled bots.

The game mode began as unfun for me as I was playing on 4 person teams. Once I had a proper game with 6 people I found it fun. An additional game mode was added on top of this called “Mann Up” where players could pay 99 cents to play a round of a modified version of Mann vs. Machine that is harder but has rewards at its end. Today, I played my first match of this type with a group of people I vaguely knew. When a wave defeats your team, you get to try again an arbitrary number of times and it took us five or six tries.

For two hours/9.4 miles I disappeared into my computer. I had to stop to get a fake Red Bull and when we were done I felt closer to those I had played with. The deck of my treadmill was slick with sweat, and my shoes made an audible squishing noise. The last time I had gotten that involved in a game, my ass was sore at the end, now the sore parts are my legs and pads of my feet.