Really cool mech game !
First off really like the whole title reference XD Then the game has a very solid retro mood, the sprites have some good detail to them the music tracks are absolute banger and appart from the smooth sprite rotation this feels really authentic to something that could have been on NES or Gameboy.
Gameplay wise i like the Left/Right weapon separation, and the fact that you can switch between 3 types at all times for each arm is a nice detail.
While the controls are solid, i feel that the choice of tank movement makes progress a bit slow, since you have to manoeuvre more carefully around shots and enemies. Though i do like this approach since this puts the game in a bit more "grounded" territory for the mechs and i feel that's what you intended here.
So overall, real solid entry, good job :)