Everyone loves new guns, and they especially love Heavy guns, because there are so few. That has been alleviated a little with the Minotaur, but lets be honest- Moar = Gud. So, I want you guys to throw out suggestions to change Light weapons into a Heavy version, excluding flak and carronade. Some might argue the Banshee is a baby Hwatcha, but they serve almost totally different roles, so it's free. So is the mortar, as the Lumberjack pops balloons, not utterly tears things to pieces. Don't worry too much about balance, it's just speculation. Here are a few I thought up.
Jupiter Field Cannon: A giant, pierce/explosive, 1 shot Mercury, with so much recoil it actually moves the firing ship backwards.
Tartarus Heavy Cannon: Heavy Hades, basically. Much more fire damage, replace pierce with shatter, high ignition chance, much smaller clip, much slower movement speed, projectile expansion, arming range, small left/right, average down, bad up. Starts off with low shot arc, but it dips sharply after awhile.