Open beta testing is now underway for Riders of Icarus, basically a soft launch for this MMORPG featuring airborne mounted combat. You can pick up the client through Steam and the Nexon Launcher. A new open beta CG trailer celebrates the occasion, and this post has all the details on what's changed since closed beta testing. Word is: "In addition to enhancements made from player feedback such as new control options, an achievement system and an improved tutorial, players can also look forward to hundreds of mythical beasts to tame, theatrical boss fights and an epic fantasy world on their journey to become a legendary Rider of Icarus."