Make sure you are using the LATEST version of GZDoom (1.0.29) or a recent SVN build of ZDoom. Older GZDoom releases and official ZDoom releases will not work! You will get a fatal syntax error in MAPINFO when trying to start the game.
New from scratch
A few days
XWE, RecolorBMP, Notepad
Sometimes sounds seem to intrude on each other's space and cut out when other sounds play, mostly because of all the footstep sounds, blood sound, ricochet sounds, etc.