ngmoco has released its iPhone first-person shooter Eliminate Pro, and, in case you've missed the build-up, it's available for free.
That's because the ambitious four-player deathmatch game, which works over 3G and Wi-Fi, is supported by microtransactions.
The method is quite interesting. You start off with a stock of power cells, and it's only while you have these cells that you earn credits, which act as experience points and in-game currency for purchasing upgrades.
Once you run out of power cells, you have to wait over an hour for the server to refresh your stock of them. This is free, but if you want to continue earning credits in the meantime then you can always buy more cells via microtransaction.
In other words, Eliminate Pro is a free-to-play deathmatch game where you can speed up your character development by investing real money, but where you can still achieve the same goals for nothing if you spend more time playing.
As you can see from the screenshots on the App Store page, it's also a pretty handsome affair for the little old iPhone, and thanks to ngmoco's Plus+ network it supports friends lists (with invites) and leaderboards.
Controls-wise, it uses two on-screen joysticks for movement and aiming, and you can fire your weapon by tapping the screen or enabling auto-fire in the options.