Ikaruga

If you are having troubles getting the 2 million by yourself you can do this achievement with two players.

The positive side with this is the fact that you get a double bonus from the boss when you kill it. Killing it will wield you about 1.2-1.3mil, the rest should come from chains.

Practice by yourself and try to get a good chain going. If you do the intro of the level right you'll end up with a 21 or 22 chain, which is a good start. The rest of the level is not that bad either if you learn where enemies pop up. Remember that you do more damage against enemies with the opposite polarity of your ship, which is needed to kill some waves before they disappear.

When you play coop, let the second player stay back until the boss, to make it easier for you to keep your chain.

I did this on easy in coop with my sister who never played this game before, we got it on the second try with 2.05mil and a max chain of 40. Very doable even for new players.

Good luck.

This achievement is actually really easy. I was surprised to see it had a ratio of 3.25. It is best to do in co-op because you get more points and you can kill the boss faster. Do it on medium becasue the enemies of the same polarity shoot at you which gives you more points for collecting the bullets. Have one person hide in the corner and have the better person do all the shooting at the beginning. You HAVE to start the game with a 22 combo. Then try to get your combo to at least 30 or 40. The goal is to get at least 800k before the boss. If you don't have at least 800k or near it by the boss just restart. When you get to the boss one person go left and one go right. Blow up the two things on the sides that shoot bullets at you. This will make it alot easier to kill the boss. You have to do that 3 times. If I didn't mention it already you also have to beat the game with neither person dying or just the one person with the big chain. Also play on default settings because I think you get more points. It's really not that hard, I've done it twice. All it takes is practice. Just a heads up. If you can't do this level then forget doing the other 4. They are much harder.