Actually I believe that "Tria" is already the plural.
The in-game word "Tria"  I suspect that derives from the word  Triangular which is the shape of the coin.
The word triangular has a Latin origin and specifically from the word "Triangulum" which has the same meaning.
Triangulum though, derives from the Greek word "Trigonon" which is a combination of the words "Tria"=three + "gonia"=angle.
The word "Tria" in ancient Greek is already in plural.

My "three" cents :-)

I run the game on both a 10.0 SuSE pro (office) & 10.1 OpenSuSE (home) system with the latest NVIDIA drivers from their site ( not the rpm package).
The only glitch up to now is that under xgl, the game does not work.
But I think that I can attribute it mostly to the fact that my VGA card is not fully supported under linux from NVIDIA. ( NX 7950 GT) 

So I would suggest to view the NVIDIA options through sax2 or YAST.
Else try to install the binaries from nvidia site. ( Though they claim that installation should be done through YAST, I find extremely easy to do it through their binary. The only drawback is that after a kernel update I have to re-run the package.

I hope that I helped you somehow

Tia
Nick