i always had an old installation of IRIX 5.3 around just to be able to play one of my favourite games: TQ (which was only available as a COFF binary). Some day i asked Bill Romanowski (the author of the software) for the sources and gladly he gave them to me.
The source is written in C and uses GL for its (wireframe and solids) graphics. You only need a small machine to be able to run it (i have an Indy for that purpose).
Due to some bug in GL the game spills out a core when you leave it - i try to fix that. Another thing is the speed of the gameplay. While it fits fine on the Indy here it might be way too fast on an ONYX2. I will try to fix that too
Here is a screenshot of the game:
And here is the link to the binary:
For those that don't know TQ: the aim of the game is to reach higher levels. You can do so by jumping into a vertex (those round shaped pulsing things) from above. So all you have to do is to jump from one rectangular platform to another to gain height and then jump into the vertexes.
My current HighScore is: Knight of the Phoenix 4th Plane