Space Pirate Trainer

The Tesla Coil is on your left and can be used to zap enemies from the first wave, Grab the Volton from your back to activate it. Youtube Link

Start Arcade mode on the first wave and then wait 5 minutes without firing a single shot.

This achievement can be made extremely easy with one simple trick. During your Room Setup for SteamVR, you can calibrate the floor. Calibrate your floor to be near the lower part of your torso. I had my room setup to be "Standing Only," I don't know if that makes a difference for this or not. If you do this, you'll be super short in game and be able to duck under the floor where a lot of shots can't reach you. Not only that, but when I used this trick two of the enemies at the beginning killed each other so I only had to worry about two shooting at me.