I just used this method (which is further detailed in the "unlocking ace" thread). This makes the game so easy, the guide should be updated (is that possible??). Using this method will easily get you all achievements but epic warrior and exterminator (175 out of 200).
There are some things to add...
I was able to do it in my 3rd try, so about 75 minutes total.
I found four catches,
- Kill the level 3's first enemies that would otherwise kamikaze into you way before you can get low enough.
- At level 4, start attaching, and if you see the first enemies kamikaze into you, shoot them before continuing to attach, they may sometimes get you before you go off screen, this is the trickiest if you are working on your own as I was, but not hard at all once you know what to do (i lost here the first time)
- At level 5, as sakura explains, just move close to the boss, and you should be fine. Actually, you can line up below to constantly him it, it will be a piece of cake. You can line up with all bosses to easily kill them , EXCEPT the last boss, which is the 4th catch.
- While fighting the last boss, I was killed while lining up exactly below it because one of the attacks gets really down. This may or may not happen, but just to be safe and not lose another run as it happened to me, avoid this position, just go to the middle of the screen and get really down (like attach 10 times, 5 with each ship, and you should be fine). Do as I say, and not as I did.
I'm writing my second and third run scores, so you can have an idea of whether you are making it or not. Please note that I'm no expert player, neither had previous knowledge of the enemies positions, nor had someone to pilot left/right, which would net you more points, and could easily get you the achievement before facing the last boss. These are scores at the end of each level:
1st level - 14,400
2nd level - 42,500
3rd level - 71,800
4th level - 95,050
5th level - 127,750
6th level - 179,500 (killed by the last enemy, which I believe its 30,000 points??, so it would have been 209,500)
1st level - 11,500
2nd level - 44,550
3rd level - 71,400
4th level - 95,700
5th level - 129,000
6th level - 197,700 (spent a lot of time getting down, just to be safe)
all runs were on insane