I think you could effectively add minigames within Zwift. Play tag, capture the flag, collect all the squirrels within an hour, save the world by reaching the radio tower in time, hide & seek, etc. You could choose a level of difficulty that would make it accessible to all.
Some games could be solo - possibly as part of a structured workout. Others would be as a group of friends, within a group ride or not, or impromptu with others “wanna play tag?”
Granted - it might be a little silly - but I also think it could be an easy add that would provide some variety and extra motivation to my workout. I mean, if the fate of the world depends on me getting to the radio tower in 45 minutes, I’d kick it up a notch to make it there in time.