I was just recently reading that it would be a good idea to write a list of the core game features I am planning to implement and offer them up for critique by other game designers. Therefore, here they are. Any thoughts you have would be great to hear.

Core Statement: This game is a multi-player life simulator set in a post-apocalyptic world.

Features:
--In-depth character customization

--Your character has his/her own needs, wants, and inherent attributes

--Through game play, discover your character's unique strengths and weaknesses which affect your skills

--Claim an abandoned house in the world as your home and customize it.

--Depending on how you deal with NPC's, they can become good friends, lifetime enemies, or even your spouse.

--Mate, raise a family, grow old and pass control on to the next generation. or die trying... You only live ONCE!

--Children inherit the traits of their parents and can be trained in various skills.

--Craft, scavenge, and fight to survive and protect your family

--Choose a faction in the on-going fight and complete opposed missions to help your side.

Keep in mind, of course, that these are not instructions on how to build the game, but just a list of features as one would find on the back of a game box.

It sounds really good. In theory; but in practice you should consider the following problems:

"You only live ONCE!" - how is this going to work? Won't players be able to kill each other? if so, what's to stop one from killing new players and making them hate the game? Even if that won't happen, when a guy manages to gain considerable wealth and he suddenly loses it all because of a stupid mistake, again you risk the player hating your game (it's realistic, yes, but that doesn't always mean people will like it).
Maybe should consider some loopholes like expensive to build resurrection amulets or something?

"Claim an abandoned house..." - how will this work in multi-player? What happens when you run out of abandoned houses for people to claim? Or what if a guy keeps a house "taken" but never - or very very rarely - plays? That's not fair to the guy playing daily but can't get his own house because they're all gone. You should consider a "house instance", a house that is different for every player but in the same place in the world for everyone. Not so cool, but safe and reliable.

Just some thoughts; I hope they help.

Hi Andrew. Thanks for the comments.

1. I guess I didn't make this clear, but part of the game is befriending NPC's and convincing them to join you as well as mating with NPC's and having children. If you have a house, they all live there and you can assign them jobs to do. If you die, you choose a friend or family NPC to become the new player character. Yes, I suppose it would still be possible for new players to die before they have been playing long enough to build up friends and relatives to switch to, but if they are that new, they won't have much to lose anyway. PVP may only be possible within missions to reduce noob ganking. It's an unfortunate necessity since some gamers are just assholes.

2. I will definitely have to kick people out of houses after a period of inactivity. It's not ideal but preferable to instanced housing which I hate. This shouldn't be a problem for quite some time though anyway since I plan for there to be plenty of abandoned places to set up base. It's post-apocalyptic so practically everything is abandoned. :-)

I see some Wurm influences already.

I think most of those sound reasonable from a gameplay perspective. I fear it might be a lot of work to get this done though.
In any case, good luck to you, I really hope you can pull this off!