Three Rings, a startup developer who formed back in 2001 to create online games, has signed an agreement with Sega to create a new action-adventure title called Spiral Knights. Supporting up to four players, Spiral Knights will feature a persistent online world and support both mouse-and-keyboard and controller schemes.

There will also be the other staples, such as guilds, crafting and customization options for characters -- and, of course, there will be some kind of in-game economy, called Crystal Energy. Check out the announcement trailer past the break.