I play many of these “.io games” and from my experience they are fun to play and very non-stressful your computer compared to a game like, Smite or CS:GO. I do feel like they are a little bit to popular it feels like going back to 2010 and playing video games from the, but the only difference is that you can play online with your friends.
I remember last year my school banned “.io games” on the school owned laptops. You ask why? The why? behind this is because .io games were easy to play in class and the teacher would never catch you because in most of these games it just looks like your simply typing, and they don’t require much skill you you aren’t hunched over the screen making quick movement.
Second of all all the .io games have the exact same goal, which is to win and become the biggest and baddest. For example in the game slither.io you “eat” other snakes to make your snake bigger.