Wii U, 3DS and PC puzzler Scribblenauts Unlimited is out this week in the US. But it's not out this week in Europe - or even this year - and developer 5th Cell is not allowed to say why.

Scribblenauts Unlimited is a Wii U launch title in the US and was originally expected to be in the UK too. That is no longer the case.

"It's due to stuff I can't talk about until 2013," 5th Cell boss Jeremiah Slaczka wrote on NeoGAF.

The North American version includes support for other languages, suggesting that localisation is not the issue.

"Scribblenauts and Super Scribblenauts were released NA and EU the same day," Slaczka added. "Trust me. I want your money. It's due to things outside of development."

Scribblenauts Unlimited publisher Warner Bros. Interactive told Eurogamer sister site Rock, Paper, Shotgun that "details about the European distribution of Scribblenauts Unlimited are coming soon".

Eurogamer has subsequently contacted Warner Bros. for more information. We'll update when we hear back.