90 dmg/turn? that doesn't sound right
In the shop-
The Gauss (lvl 10) 20-32 dmg
Heavy gauss (lvl 12) 34-47 dmg

It's not until the lvl 30 6tuplet rockets, that 90 dmg can be done, and there's no way you should be fighting any of those guys at your level.

If you are experiencing this, then it's probably a bug, my advice would be to try and get a screenshot of this happening, and post it in the bug section.

I like this guy he has a lot of positive feedback for the game

a turn is 2 actions; if you use 2 "Heavy gauss (lvl 12) 34-47 dmg", u can dish 94 damage per turn. I think he meant that way...

To counter rockets, use either HP upgrades to endure them till they Rockets deplete (makes them useless, no rocket no damage), or make a balance with HP and resistances. Armor Plate 6 Module x3 is fine to get and it will probably make your enemy use all rockets w/o killing you. There is a Threetop Body at lv12, getting can be good.

p.s. or just keep enemy close forgot this tip Charge/teleport/gripper are there for you. Since that Heavy Gauss thing has 4-8 range, 1-3 range=he can't use it

Happy hunting!

Okay, that makes sense now.
I think rocket weapons are balanced. They are more powerful, but they use ammo, which is limited.
And even though you can boost ammo with modules, it means those module slots aren't being used for health.

Although, if you're a level 9 facing a level 12, most weapon can kill you in a few turns.

So overall, all the weapons are balanced for their own levels, but I agree that the difference between levels may be a bit high.