: Marathon: Durandal for XBLA's survival mode has code not to upgrade monsters
: in TC, so there is some variety of color :)
What's more, if you start a level on, say, Normal, and save your game, you can come back in Total Carnage or whatever and it won't change monster ranks or placement. Up for Green Fighters, anyone?
Of course, once you leave that level and move on to the next one, then everyone will be back to Blue and Purple and what-not. Also, you could take the alternative route and start on Total Carnage or Major Damage, then save and come back on Kindergarten or Easy or whatever. The result is a 'fine-tuning', if you will, of the difficulty - everything is as weak as it would be on an easier difficulty, but there's more guys (if you're going below Normal) and they're all Majors (or mostly Majors, if you started on Major Damage), or you could have a vice versa effect (less Majors, stronger guys all around).
Don't you just love Marathon? It makes everything so easy for you! Well, until you realize that you don't have enough health to jump that slime, can't recharge, and can't revert to a save from before the problem struck. Then it's just plain cruel.
Vale,
Perseus
