I am a big metal fan. But unfortunately I have to admit that I don't know the participating musicians / bands. MOONSPELL is the only band from Portugal that I know and have seen in several concerts .[/quote]
They are Portuguese by birth, but, for practical purposes they seem much more a German band to me. I mean, MOONSPELL.
About the Portuguese metal scene, being an almost completely unknown world to me, I launched a search and found reference to a documentary.
Here's a link to a 15 minute excerpt (think its about 1 + 1/2 h for the complete / commercial version).
No music in the excerpt, its composed of musician testimonies, but they're identified by their participation in bands/projects, so you may dig for info/music if you can find the time.
English subtitles are available.