Survivalist is an RPG/RTS where you aim to build a community of survivors in a zombie apocalypse. You'll search for food, build your base, recruit new members, trade with other communities, go on quests, and uncover dark, terrible secrets. It's an XBox Live Indie Game (XBLIG) but don't let that put you off.
The game is currently in playtesting in the XNA Creator's Club. So it's not finished but it's pretty close. Hopefully it'll be released in early 2014.