I wasted the most (36 shots) in the first electrical map, "electrical problems", trying to hit a small piece of iron wall hoping it'd electrocute the enemy. When I finally hit the wall, the enemy didn't get electrocuted for some reason. It was only then that I noticed I could choose my weapon.
I gave it a try some days ago but i should have read the instructions because i couldn“t do shit.
Yeah, I skipped the instructions as well, which led me to waste an awful lot of shots in the first map, trying to hit the ramp directly.