I just recently finished Service Workies by Dave Geddes. It is a video game style tutorial that teaches the player how to use Service Workers. It's not simply the gamification of learning, but an actual game with engaging graphics, music and story.
The concept is based on the idea that expertise is attained when you repeatedly do something. Video games are a good example of this and he uses those techniques to solidify concepts and drill in practice. Although I'm not really a gamer, I find this style of tutorials to be really creative and fun!
After a quick look around, I've found a few other games in the same vein:
What's your experience with these type of games? Do you think they are an effective way of learning?