I doubt German economy is particularly strong, though other countries have it worse and everyone sees their own problems more clearly than others.
AFAIK Germany is the strongest economy in the EU at the moment. So stronger than UK, France and all the other countries in the EU (most of which do not count much anymore, especially the southern countries).
The only economies that might be challenging Germany on the continent are small countries like Switzerland, but then that is a much smaller economy partly shielded from the turmoils of the current Euro crisis, and no country of interest for a game dev.
So yeah, Germany is about as good as it gets in europe. If not stronger, economy is level with UK and France, and as far as I can tell from the news, Germany has still much less social problems than those countries (if we leave aside that Pegida stuff), and a strong and well respected government (Merkel might not look happy on the Pictures, but she seems to be one of the better politicians in europe at the moment).
Be advised that, if you have missed that in the news in Brazil, the Euro is still not very stable, there is still an economical crisis going on thanks to multiple factors in the EU (the new government of Greece not particularly helping here), and most probably you know about the stuff more east from here in the ukraine which directly affects europe and germany especially as europe was always quite happy buying russian gas for energy and heating, which of course is no longer as cheap and easy to get as it used to be.
Apart from that an the weather (Hamburg is quite north), I think it is quite a good place to live.
The only real pain is the language. German is quite hard to learn for foreigners... good thing is, as Europe has an incredible amount of different languages spoken in a rather small area, most big cities are usually multilingual, you shouldn't have any problem getting understood in these cities with english, maybe french, italien or spanish to a lesser degree.
Portuguese of course is rather a stretch, Portugal is a very small country at the western border of europe, so you will not find many people in other european countries going through the hassle of learning portuguese when they could instead learn french, english or german. Some spanish or italian speaking people might still understand you though...
Anyway, I recently saw some statistics where employers would care much more for alignment with their firm philosophy, work ethics and other things than exactly what degree you got (as long as you have one).
And then there is the fact that the more work expierience you have, the less a potential employer will be looking at your diploma. Someone with 5 years expierience in the field and a bachelors degree might actually be higher rated on the job market than somebody with a masters degree but no work expierience