decl String:folder[30];           
GetGameFolderName(folder, 30);           
if(strcmp(folder, "cstrike") == 0)           
{          
           //CSS
}          
else if(strcmp(folder, "csgo") == 0)           
{          
           //CSGO
}          
else if (strcmp(folder, "tf"))
{
           //TF2
}
else if (strcmp(folder, "hl2mp"))
{
           //Half-Life 2:DeathMatch
}
else if (strcmp(folder, "l4d"))
{
           //Left4Dead
}
else if (strcmp(folder, "l4d2"))
{
           //Left4Dead 2
}

new version = GetEngineVersion();
switch (version)
{      
case SOURCE_SDK_CSS:      
{      
// ксс      
}      
case SOURCE_SDK_CSGO:      
{      
// ксго      
}
case SOURCE_SDK_DOTA:      
{      
// Дота      
}       
case SOURCE_SDK_LEFT4DEAD2:      
{      
// left 4 dead 2      
}       
case SOURCE_SDK_LEFT4DEAD:      
{      
// left 4 dead
}
}