From Valve Developer Community
From: 
Half-Life: Uriel
// Valve Game Info file
// These are key/value pairs. Certain mods will use different settings.
//
game "Half-Life: Uriel"
startmap "uriel_a1"
trainmap "t0a0"
mpentity "info_player_deathmatch"
gamedll "dlls\hl.dll"
gamedll_linux "dlls/hl.so"
gamedll_osx "dlls/hl.dylib"
secure "1"
type "singleplayer_only"
