i did beat level 40 boss on hard on like level 20 something and still you get the achievment

so you download the editor pack from indiedb and copy the alien shooter tower defense files into the files fo alien shooter tower defense if you want more clear instructions message me

How do you do that lol

yk you could just map edit the level with tons of extra soldiers

The rocket launcher dude is good at dealing with massive amounts of tiny enemies with his most powerful weapon on top of everything else sometimes

Tip: I used A LOT of mines, like, A LOT... those explosives are the only reason Nightmare mode is possible on most levels (and pretty much all the later levels) other than the laser gun guy's most powerful weapon which is pretty much the only thing you need to fill out the levels with as well as the freezing special forces.