Upgrades is a feature that helps to improve your tank in different ways. There are 7 upgrades right now. When a player re-spawns their upgrades are reset and they receive the proper amount of points based on their Experience.
Reload
Every upgrade increases fire rate and use of energy.
Damage
Every upgrade increases your damage, bullet size and use of energy.
Speed (Removed)
Currently speed is determined by how many upgrade points have been spent on your tank. The more points you spend, the larger your tank becomes and the slower you move.[1] A level 55 tank with 55 points available will be just as fast as a fresh level 1 tank.
Health
Every upgrade increases maximum hitpoints by 90.
Heal
Every upgrade increases your health regeneration.
Energy
Every upgrade increases your maximum energy. This allows for longer periods of continuous fire. However, your meter will never read above 100%, so this upgrade is only noticed while firing.
Recharge
Every upgrade increases your energy recharging speed.