I'm going to try this method now. I've made it a point to try and get as many in-air kills as possible so far, so hopefully a couple runs through the level will put me past the number for the achievement. I'll post back in a bit with my experience.
Still trying, and I have 8 so far, but here's a question I came up with: When you kill the Knight, do you also have to kill the slug-looking thing enemy that comes out of it with a grenade? Does that technically count as the "enemy," seeing as it comes out of the Knight?
100% Retail: 18, 100% Arcade: 7
Last edited by The Incendiary; 04-25-2010 at 01:55 AM.