"Eliminate," from "Rolando" iPhone developer ng:moco, is definitely blazing some new ground on the platform, offering up a free-to-play 3D FPS in a market that's over-saturated with simple match-3 puzzle games.
To understand what's so experimental about the game, you have to understand how ng:moco plans on making money on a title that's free. Imagine an RPG where killing foes earns you experience with which you can upgrade your character. But, once you've played for a certain amount of time, you'll cease getting experience. You can still play for fun, but your character will not progress until your time meter fills up again.
That's how "Eliminate" works, but in FPS format. You'll earn cash from enemy kills, but only if your meter has juice in it. After about 3 games it'll be empty and you'll stop getting money for upgrades. That's where the profit model comes in. You can buy batteries for real-world money which will instantly refill your meter, letting you play and progress your character without having to wait for the meter to fill up (which takes about 12 hours).
For one dollar you'll get 20 batteries, but it takes 12 batteries to fill the meter, which means you're getting only about 6 rounds of character progression before you'll need more juice. You can buy bigger packs of batteries (280 for $10 and 975 for $30), but if you're stingy and patient you can play "Eliminate" for about 10 minutes once a day and get your fill. It's almost like turning on "Animal Crossing" to harvest fruit, but with more rocket launchers.
As a game, "Eliminate" is a pretty simple "Unreal Tournament" knock-off, with some character progression thrown into the back end. Its most impressive aspect is the fact that it's extremely playable over 3G (and even better over WiFi), so you really can hop in a multiplayer FPS while you're, say, on a bus.
There's really no reason not to give it a shot, if only to try a cool experiment on what's still a bit of a Wild West platform. Whether the gambit ends of paying of for ng:moco, time will certainly tell.