OK, I finally managed to get Kingpin to work on my PC using "zeckensack's Glide wrapper", it's running pretty fine
Now, I was looking at some cheats over the web and found this possibility to play original Quake 2 maps on KingPin (you have to extract Q2 maps and textures and place them into KP directory), so my question is: does it really work? can you actually play Quake 2 single player through Kingpin?
Thx