Thanks for letting us know.
The art license of 0 A.D. is CC-BY-SA 3.0
https://github.com/0ad/0ad/blob/master/LICENSE.txt (it says there are further license text files in the art asset directories)
This appears to be a common practice HTML5. The biggest advantage is less files to download, I'd say.
This got discussed in a HTML5 game dev podcast that I recommend:
Hi and thanks for asking,
CGtextures' works and derivatives are prohibited from being freely licensed (cc-by, cc0, cc-by-sa, gpl) but only freely licensed works are permitted on opengameart. Therefore CGtextures' works can't be used in works submitted to opengameart.
Hope this clarifies it.
Is there any reason to prefer .tga over .png? I would expect png to be wider spread and easier to load than tga. Tga seems to have the disadvantage for downloaders, that compression is optional (as far as I know, compression is mandatory in png).
I have a tutorial for that as well actually ^^
My recommendation is indeed to use the username and ideally link to their user page.
http://creativecommons.org/licenses/by/3.0/legalcode Sections 4.a./4.b. specify what attribution requirements exist by default.
Please attribute "Iwan 'qubodup' Gabovitch" or "Iwan Gabovitch" if it doesn't fit the style/width of the remaining credits. If possible, make it link to http://qubodup.net or http://freesound.org/people/qubodup/. Not required in this case though.
CC-BY requires attribution, in case you didn't know and were using other sounds under that license.
Thanks! I hope these are useful and good luck with the release.
Since you decided to give gender to the elementals, why not a 50/50 distribution?
Here's a recording of the lines. Hope it will be useful and that you'll share the results on OGA.
It'd be curious to know how you edit them as well. I have a bunch of Audacity tutorials, which might or might not be helpful for this task: http://www.youtube.com/playlist?list=PLnmtnFt6ekNVdb2DqNbbkAmHVWXbeShWS
So happy! xD