Well, I finally got it. God. This one of those achievements that I hate. While you are trying to get it, you are telling yourself, "why am I even doing this? This isn't fun. It's just pissing me off." And when you get it you tell youself, "I'm glad that shit is over with." There are just too many random things that could happen. Especially with the two robots near the end of stage one. It's hard to come up with a strategy when the missles could home, or they might not. Or the robots might shoot two bullets in a row. Or they might space them apart. I even noticed that the stage one boss has a random period of invincibility when the head first pops out. Sometimes you can damage him right from the start but othertimes your bullets won't do anything for a little whil.e If it lasts long enough (about 2.5 tail swings) then you're screwed because by the time he gets close enough to you, you die and you didn't get a chance to do enough damage. It's so frustrating to make it past the two robots (the hardest part of this achievement imo) and die to bullshit like that.
Oh well, like I said it's done and over with. I just played a that dealt me the right cards.