Rename -game to -play & Fix when play not used.

Source/Engine/Engine/CommandLine.cpp

@@ -151,7 +151,7 @@ bool CommandLine::Parse(const Char* cmdLine)
     PARSE_ARG_SWITCH("-build ", Build);
     PARSE_BOOL_SWITCH("-skipcompile ", SkipCompile);
     PARSE_BOOL_SWITCH("-shaderdebug ", ShaderDebug);
-    PARSE_ARG_OPT_SWITCH("-game ", Game);
+    PARSE_ARG_OPT_SWITCH("-play ", Play);
 
 #endif
 

Source/Engine/Engine/CommandLine.h

@@ -156,9 +156,9 @@ public:
         Nullable<bool> ShaderDebug;
 
         /// <summary>
-        /// -game !scene! ( Scene to play, can be empty to use default )
+        /// -play !guid! ( Scene to play, can be empty to use default )
         /// </summary>
-        Nullable<String> Game;
+        Nullable<String> Play;
 
 #endif
     };