Sometimes, weapons are made so accuracy is not a top priority. Roller fills that spot with simplicity. Upon landing, it will continue to roll in the direction it approached the ground from and deal 20 damage upon making contact with a tank.
What's better than a weapon you only have to aim moderately accurately with a likely chance of hitting? A weapon you only have to aim moderately accurately with a likely chance of hitting that does double the damage! Although it does double the damage, be careful because it doesn't travel as far on the ground.
Much like it's predecessors, Groller rolls across the ground, but as it rolls it grows larger and larger, building up damage. When it reaches the final form, it will deal 48 damage.