Turn on cheats
sv_cheats 1
Noclip + noclip speed
noclip(on / off)sv_noclipspeed 0.3(default 5)
Remove HUD and viewmodel
cl_drawhud 0(1 to re-enable)r_drawviewmodel 0(1 to re-enable)
General cheats
ai_disablenotargetgod
Change map
map <mapname>use list at https://developer.valvesoftware.com/wiki/Half-Life_2_map_reference
Demos
record <demoname>playdemo <demoname>