Otherland, the ambitious MMO based on Tad Williams' cult science fiction books of the same name, has emerged from hiding, nearly four years after it was first announced.

Developer RealU has released the free-to-play title's first gameplay trailer, which you can see below, and confirmed that game is scheduled to go live some time this year.

In case you've forgotten - we certainly had - Otherland is a mind-bending cyberpunk adventure set in a virtual reality multiverse.

Confused? Our Otherland preview offers a more in-depth explanation of what the ambitious title hopes to achieve.

"The appeal of Otherland's basic premise - an MMO that has the potential to be anything you want it to be - is as easy to grasp as the specifics are hard," wrote Eurogamer's Oli Welsh back in 2008.

"It must be one of the most original, thought-provoking and intellectually exciting games in development anywhere, and although you might be a fool to bet on its success, you'd be a churl to bet against it. Because, in the all-too-conservative world of MMOs, Otherland is exactly the kind of unlikely story we need."