On day 13 I bought my first weapon. 100 gunmen helped that.
Way too easy with the gunman, but if you don't get em, it is actually challenging. I'd definitely give it a 4 if the gunman were balanced more, but currently a 3 / 5
If the enemies spawned only ever off screen, then you wouldn't get anywhere near a decent amount of pips, and the spawns are there to make you think more tactically, instead of just moving around all the time. You only hit them as they spawn because you're moving too fast.