Terraria: Otherworld is a newly announced follow up to the 2011 crafting and survival game, but it's not a sequel, according to the developers. In an announcement on the official Terraria forums, collaborating studios Re-Logic and Engine Software stress repeatedly that it is not a sequel. Which is fine, but what is it?

There's not a heap of information out there at the moment (the studios are inviting fans to speculate on the forum) but according to the official line, Otherworld will "explore what might have been, and approach gameplay in a new direction".

"Set in an alternate dimension within the Terraria universe, Terraria: Otherworld places the player in a life-and-death struggle to restore a once-pristine world – now overrun by a malevolent force that has corrupted nature itself – to its original splendor," the announcement presser reads.

"Along with a rag-tag band of survivors, will you be able to successfully harness the power of an array of weaponry, magic, defenses, and even the world itself to thwart the designs of this unseen evil?"

The game will be on display at GDC next month, so no doubt we'll hear more about it then. In the meantime, why not watch the teaser trailer below, which shows a very familiar looking Terraria setting.