Image via les studios Lowtech
Mobile IO games come in all genres and types, although they have two things in common: they are free and have light graphics. This means that most, if not all, are accessible on any phone, regardless of age or low RAM.
But there are quite a few online. That said, we are listing the best and most convenient ones for playing on mobile.
Slither.io
Image via les studios Lowtech
Slither.io is based on the classic pellet-eating game Snake, and plays exactly like it too, with the added challenge of other players on the map that you need to avoid. Each Slither comes with 16 default skins, though you can customize its appearance with weird textures, country flags, and even colors based on popular YouTubers like Jacksepticeye.
Agar.io
Image via Miniclip.com
If you've played Osmos, you know exactly what to expect with Agar.io. You control a blob whose goal is to be the biggest blob on the board. Unlike Slither.io where you eat pellets, however, your Agar.io blob will only grow by eating other blobs, which are controlled by other players. It's extremely competitive, which makes it a lot of fun.
Related: Best mobile multiplayer games
Axesio
Image via CASUAL AZUR GAMES
For a genre as rare with its resources as IO, AXES.io is perhaps the finest game of the bunch. It's a 3D arena battle royale game, where the goal is to throw axes at other players until you're the last one standing. AXES.io features both online and offline play, over 40 types of axes, and over 20 hero designs.
Noodleman.io
Image via Riovox
The goal of every noodleman is simple: throw all other noodlemans out of the ring. However, there's a catch: each character has a "soft body," meaning they have bouncy shaking physics. It can be difficult to fend off other players and even change direction. As a result, each game passes very quickly, making Noodleman.io the perfect game for quick breaks.
Hexar.io
Image via MochiBits
Hexar.io is a land capture game with gameplay mechanics similar to Pokรฉmon Rangers. You are assigned a color and the goal is to dominate most of the board by enclosing other hexes (both unoccupied and occupied by other players) with your own. This is done by dragging circles around your screen. It requires a lot of real-time strategy, so it's great for players who get into it.
If you're looking to check out some other great mobile games, take a look at our picks for the best offline mobile games and the best mobile MMORPGs here at Pro Game Guides.