Death Rally is a great iOS title from Remedy Entertainment, the makers of the Alan Wake game for the Xbox 360 a little while back. (Quick disclaimer: I, Mike Schramm, actually have a cameo in the game, for turning in a solid time at a press event. But I wasn't paid at all for my appearance, and I don't make anything from sales of the game. I legitimately think it's a great title, though.) The game has just gotten a big update that adds something players might be surprised by: multiplayer. Up to four people can now load up the game, and race against each other using the Shrieker car, on up to six different maps, including Eureka, which was previously only available via in-app purchase.
The update also adds a new weapon, the flamethrower, available from an in-app purchase reward pack, as well as a new paint job for one of the cars, and some enhanced graphics on the iPad 2. I have to say, iOS 5 support would have been nice (it's kind of a pain to have to re-do the game on the iPad if you've already played on the iPhone), but considering the update is completely free, I can't complain too much.
If you haven't picked up the game yet, it's available for just 99 cents as a universal version right now. Good luck trying to blow me up in the game -- you'll get an achievement for it if you do.