io games   have been popular for a long time, and they're a great way to kill time whether you're alone or looking for something to do with a friend or two. Diep.io is one of them.

Diep.io strategy guide 
Need help upgrading your tank and levelling up in Diep.io, an Agario spin-off? Diep.io strategy guide. Agar.io and Slither.io’s successor, Diep.io, is sweeping the internet. Diep.io is similar to Slither.io, but it has some twists that make it different.
We’ve created a beginner’s guide to playing Diep.io and levelling up without cheats if you’re still confused about tank classes, when to upgrade, and what stats are best.
First, you play as a small tank instead of a blog or snake. Like Agar.io and Slither.io, the goal is to become the biggest, baddest tank by destroying other tanks. Diep.io requires more skill than knowing when to dodge or dash. 
Visit Diep.io, enter a username, and you’ll be taken to a familiar game grid with your tiny tank in the middle (blue circle with tiny grey square attached).
Shoot to level up.Colored squares, triangles, and pentagons are game obstacles you must shoot to level up.
Point your mouse at your target and press the left mouse button or space bar to shoot (alternatively, you can hold down either the left mouse or space bar for continuous shots).
Arrow keys move the grid.
Destroying shapes or tanks fills your tank level bar. Level up when full.
When your tank levels up, you get a stat point to upgrade health, bullet speed, penetration, and eight district stats (more on those below). Each level until 30 earns a stat point.
Level 15 tanks can choose from four tank classes. Class, like stats, adds a unique element to gameplay (more on tank classes below).