Mouse type
From OdaWiki
mouse_type
0: Use ZDoom's default mouse handling.
1: Use Odamex's custom "Standard" mouse handling.
By default, ZDoom handles mouse movement in an entirely different way than doom2.exe, which causes some discomfort to players who are used to doom2.exe's mouse handling. Setting this variable to 1 attempts to emulate doom2.exe's mouse handling as closely as possible.