As long as you have the required energy and weapons you'll complete the mission and get the cash and experience. After a while, you'll run out of energy and then have to wait until it replenishes. Periodically, your experience will win you a new level, which adds to your strength as well as your selection of jobs. No, it's not a challenge to progress, but it is a challenge to stay away. Seriously, the thing's like the Sopranos version of a Tamagochi.

We're simplifying, of course, there's a lot you can do with your easy-to-earn power. You can use your cash to buy property which turns into an ever-accumulating revenue stream. You can battle other gangster to take a slice of their pie. Or you can recruit friends to join you in your mafia and (if you're utterly without scruples) rough them up for some of their dough.

One of the few quibbles we have with the game is the randomness of these battles. Even if you outclass an opponent in every way, there's still a decent chance you could lose. That kind of unpredicability is an irritating counterpoint to the reliability of doing jobs.

It may not be much of a game, but if you need yet another reason to compulsively check your iPhone, you could do a lot worse.

Mafia Wars (Free, Zynga):