01. Agario

Agar.io is one of the simplest games that you can play out there. The idea here is that you enter a world full of bubbles and you have to eat them in order to become the largest bubble. That may seem like a simple premise, but a ton of people play this just because it's a ton of fun and you can enjoy this again and again. People really like this game because it's adaptable, exciting and it definitely delivers one of the most interesting options when it comes to casual games. Agar.io also comes with multiple game modes. There's the regular free for all, and then you have teams, experimental and battle royale. Every one of them has its own twists and turns, which actively makes a game like this extremely interesting and actually very fun, if you like something like this. That being said, this is one of the simplest and funniest casual games. So if you want to have a good time while you play games, this is one of the best options out there!