There are 8 different stat upgrades you can use. When you level up your tank, a stat menu appears to the left of your game screen. Below are the stats you can choose from. You select a stat by tapping on the plus sign beside each.
Health Regen - Increases the life recovery rate of your tank
Max Health - Increases the maximum life
Body Damage - Improves the damage caused by collision with other players or obstacles
Bullet Speed - Increases the speed of the projectile
Bullet Penetration - Bullets go through obstacles and players
Bullet Damage - Improves the damage caused by projectile
Reload - Interval decreased bullets
Movement Speed - Increases movement speed of your tank
Each of these stats obviously brings its own sets of benefits and as you think about the Tank class you are going to choose, you’ll want to add complimentary upgrades. For example, snipers load slower so you’ll want to make their shots count. You’ll also want to consider the types of players you see on the board at the time. If the server is loaded with players, for instance, health upgrades might come in handy.