The Heavy Gunner is a premium unit that costs 20 and is unlocked at Level 17. It requires a Level 4 Barracks and a Weapons Factory.
The Heavy Gunner acts as an upgraded version of the normal Gunner, offering a wider attack pattern and more . With Wide Spray, it deals 9-11 (x4) damage over a very wide area. Placed in the front row, a Heavy Gunner will cover a 2x5 square area, potentially attacking up to 10 units. It also has an Anti-Air Wide Spray to hit air units as well, though somewhat weaker in base damage.
However, as it is a premium Nanopod unit with underwhelming improvements from the Gunner, players should consider that the normal Gunner gains ranks much faster, and thus more damage output. This is compounded by the fact that the Gunner has access to a second attack type that greatly increases their damage output. This relegates the Heavy Gunner to a niche role for players who can afford the time and resources to purchase them and rank them up.