Greg, you officially have no life!
I did about 1,800,000 on excessive on my third try, but I know I’ll be playing this game for a long time to come so that score should be quickly eliminated. If you guys haven’t played the game on excessive, try it now!
Lol . . . when they say excessive, I think it’s not excessive in terms of difficulty, but excessive in terms of computing horsepower required!
Like Battle Cat said—circling is key. The whole point of the game is to clear a path. Grenades are good for doing that, but the main idea is to keep blasting around in a circle as fast as possible, while watching out for opening doors.