St. Proverbius mode
Arg! you can't call it St. Proverbious mode. I already dubbed it Ironman. (ment to be humor do NOT take too seriously). Check the FO2 board, I've been playing that way for some time, only reloading from saves in case of a bug or crash. I'm on my 10th time I think, I still haven't been able to survive to the end even with easy gameplay and combat. I almost made it to sanfrancisco once, but fought when I should have run... admittedly I can't imagine a game that would ONLY have this mode, it'd be hell (as I said I haven't managed to finish yet playing this way, but it sure extended gameplay)
To Doom etc. you should be lucky to make even a single character, and to be able to customize your other ones as they level in a "tactics" game. Most tactics type games don't let you do either, a few they don't even have stats you can see, and are just cookie cutters. If you mention JA or X-COM I'll have to smack you around, niether let you make any characters, and customization as leveling occurred was pitiful or non-existant. Most RPG's only let you make your original character (a few let you do the whole mess, like gold box, or Balders Gate if you really wanted to read through everything and go through a ton of hoops).