It's a fairly shameless marketing ploy, but we're biting because the developer of the awesome N-Gage game Hooked On: Creatures of the Deep is also giving away an iPhone 3GS, and that's the kind of bait we like to chase.

The developer is gearing up to launch its second iPhone game, but instead of just announcing it Infinite Dreams is asking you to guess what it's going to be.

A series of five YouTube videos are planned that will lay down a trail of breadcrumbs leading to the answer. You're being invited to check out these teaser trailers (a new one will be posted every two days) and tell Infinite Dreams what it's planning in a few short words.

The first clip is below, and is cryptic enough to ensure this one alone is unlikely to furnish us with an accurate guess. Keep checking in on the developer's official YouTube channel and contest page for the others. Don't miss any, or you might miss out on that shiny new 3GS.