Gigapocalypse (EP)

You need to destroy 10 Totems, across separate runs. It can be found on the beginning (usually the first minute or so) of Wild West 1. When you see it, shoot it to destroy it and hit cn_start, select upgrade to take you back to the menu, and do another run. The appearance might be a little RNG-dependent, so if it doesn’t show up in the first 60 seconds or so, quit out and start another run. Took me about 10 minutes to unlock after about 15 or so tries.