I spent far too much time playing Guns of Icarus this morning after seeing it on IndieGames's convenient link-round-up. Developer Muse Games (Elementia, Extreme Sledding) recently entered the title into the IGF 2010 Main Competition, and released a trial version that you can play in your browser.

The Unity 3D-powered game has you manning an airship in "an apocalyptic steampunk future", shooting down pirates and repairing your craft. If you make it to your destination (you'll have multiple branching paths with varying difficulty to choose from) with enough undamaged cargo, you can upgrade your ship's armor and weapons (e.g. cannons, tesla gun).

Guns of Icarus's full/paid downloadable PC and Mac editions feature 19 levels, 8 gun types, an "Into the Breach" mode, and a fullscreen and high resolution player. Both the free and paid versions also have a four-player mode, which I unfortunately didn't get to play due to the current lack of open games -- this looks like a really fun multiplayer experience, too.