Someone on Steamgifts contacted Nuuvem support about it and it seems Nuuvem themselves don't know.
"Lmao at their support : they answered me in spanish. And it's a Br website.
Anywho, their response was quite fast for what's to be expected from support tickets.
The response was lolworthy too: they have no idea if it works outside of south America. It's that plain and simple. There's no region lock in any country of South America, but outside of it, they have no guarantees (nor will they look into each case individually it seems).
All I can say further is - I've never had any problem activating any game bought from Nuuvem in Portugal. It's a gamble to get in on this offer, but it may pay off.
=)
EDIT - since they reply so fast, perhaps other people could email them and try to get a more concrete answer?
EDIT2 - This reply might be a way of avoiding accountability on their part and keep their prices competitive (and enabling us to buy in R$ instead of the more expensive $ or € )"
Post edited August 18, 2013 by Gonchi