Agar.io is the 'classic' of the .io genre, but it’s showing its age. It’s a great way to kill ten minutes, but the transition to mobile has brought some nasty monetization habits.
The $8-a-week subscription is frankly offensive for a game this simple. If your kid is playing on a browser, it’s a relatively harmless time-waster, provided you’ve had the talk about ignoring the inevitable 'edgy' usernames. Just don't expect it to hold their attention for years like Minecraft or Roblox—it's a snack, not a meal.


