I've done it! I've finally got Quake to run on my DC! Heres the proof:
I had to download a Utopia boot disc and burn it with Nero, then I downloaded the Quake executable files and put those on a CD-R. It works great and is basically just the PC version. It has all of the intro hub levels (where you choose your chapter and difficulty etc) and can be played with either a keyboard/mouse set up or the joypad (the layout is like Turok's with the analogue for looking and the A,B,X,Y buttons for strafing. D-pad changes weapons, R is fire and L is jump.
Overall, the game has a very good frame rate and is pretty sharp, but I feel it looks a bit Quake64-ish due to the slightly blurry textures. However, it's another addition to the 'Yard, and my second successful DC download after the DivX player I got a few weeks back. If you want some Quake action on your DC, follow the link to QuakeDev on the right. Alternatively, if you send me two CD-Rs and an SAE, i'll hapilly burn you a boot disk and a copy of Quake. Email via my profile.