From Valve Developer Community
From: 
Alien Swarm
"GameInfo"
{
"game" "Alien Swarm"
"title" " " // asw - leave this blank as we have a texture logo
"type" "multiplayer_only"
GameData "swarm.fgd"
InstancePath "tilegen/instances/"
SupportsDX8 0
"FileSystem"
{
"SteamAppId" "630"
"ToolsAppId" "211"
"SearchPaths"
{
"Game" "|gameinfo_path|."
"Game" "swarm_base"
"Game" "platform"
}
}
}
