My friends pointed out
www.nexuswar.com
to me recently. It's evolved from the original
Urban Dead game, with similar mechanics. Helps me out, because I'm a compulsive game player. Each character is allocated a set of "Action Points" (AP) which they can use to fight, explore, search, talk, or do anything else. A normal character can hold 50, which is easy to burn through in about 10 minutes. A free account gets three characters, so that's 1/2 hour of game playing.
The AP regenerate at a rate of 1 every 15 minutes. It means you can play about twice per day. I get to play my half hour of computer games in the morning, then again in the evening, and there's no point in staying antisocial for any longer than that, 'cause I can't do anything.