erk... I think the universe just shifted under me.
Are you guys saying, use the rules as is and just change the flavor text?
I was taking the tak of comming up with actual new races and classes....
Nope, read my other posts...I would definitely not do anything like that.
To just change flavor text and work within the existing rules as is to me would be a rules light model. I would probably add some crunch to the system.
Example...For any mutant character, I would have a random chart with say 40 or so At Will Mutations that are generated, you guessed it, RANDOMLY. These would scale with your character a lot more often then at 11th and 21st level.
I would also probably add a system for "defect" mutations, and varying levels of those to account for adding more positive mutations to your character.
All the classes would need to be reworked, and I probably would drop several of them (No clerics, paladins, warlords). Contrary to another post, I would make sure Healing Surges were quite normal, to alleviate ever needing any type of Healing class. Though I don't mind my GW to be gritty, I would still want healing surges to make up for the loss of the cleric class.
The balance of how to break down race and class will be tricky, as to where you draw the line of determining Mutant Human, Mutant Animal, or Mutant Plant...and of course the good 'OL PSH. You could also use the Mutant Future method and add Androids.