There have been a number of shooters since the iPhone launched, but the control limitations of just having a touch pad have made them hit or miss affairs. Recently, though, we saw the release of three strong shooter entries which are definitely worth checking out.
"DOOM Classic" ($6.99)
I was particularly fond of the port of "Wolfenstein 3D" on the iPhone, and John Carmack has brought the same level of quality to "DOOM Classic." It's classic "DOOM," complete with the 4 classic episodes, all the weapons and even some multiplayer options (playable over the same WiFi network). As someone that didn't really play much of the original "DOOM" when it first launched, it's hard to blame my enjoyment with this game on nostalgia. Fact of the matter is, even after all these years "DOOM" still holds up, and Carmack has done a fantastic job bringing it to the platform.
"Big Buck Hunter Pro" ($2.99)
I've played my fair share of "Buck Hunter" in bars across the country (and even in the MTV newsroom!), so I was curious to see how it made the transition to the iPhone. From a gameplay and presentation perspective, the developers have done an excellent job, as the game looks spot-on with the full-sized counterpart. Unfortunately you'll have to trade in your orange shotgun for your finger when it comes to aiming and shooting, which definitely takes some of the enjoyment out of it, but not to a terrible degree. I will say, though, that there should've been a bit more content thrown our way, as the iPhone version only has one animal to hunt, versus the myriad that are in the arcade version. I'd guess there are plans for DLC in the future, but right now it's not quite the complete package. That said, if you're a fan of the arcade version, this is your best portable option.
If you haven't played this quasi-free, 3D first person shooter, you're definitely missing out on one of the more polished iPhone titles out there. "Eliminate" manages to cram a 3D multiplayer shooter, playable over 3G or Wifi, onto a device that was, at one time, inundated with "Bejeweled" clones. And considering the pricetag, it's hard to deny. Just keep in mind that if you feel the need to advance your character at a steady rate (i.e. more than once or twice a day) you'll have to pay for it.
Bonus Update: "Bejeweled 2"
In extra added news, if you are one of the millions that bought "Bejeweled 2" on the iPhone, make sure you hit the update button in the App Store. Games.com had the first-look preview of the newly added "Blitz" mode, which allows you to sync your best scores with your Facebook page and see how you rack up against your friends. Again, a free update if you already have the game, so there's no reason not to.