To disable startup videos for the Steam Mac version of XCOM:Enemy Unknown do the following.
Follow these instructions at your own risk. There is no guarantee that these instructions will work for you. I am not responsible for any damage or loss caused due to carrying out these instructions.
- Find the file DefaultEngine.ini in
- [recommended] Create a backup of the file. I called mine: DefaultEngine.ini_backup
- Open DefaultEngine.ini using your favorite text editor – I used Sublime Text 3.
- Locate the header
; PC Startup movies. The exact line number may vary depending on the DLCs you have installed. For me it was on line 1957.
- Add a semi-colon (;) before the first four lines that start with
+StartupMovies=. The semi-colon comments these lines out. If you like, you can include an optional space after the semi-colon. Leave the
+StartupMovies=[screen_x_resolution]x[screen_y_resolution]_Blackline as it is.
- Save and close DefaultEngine.ini.
- Startup XCOM: Enemy Unknown. If goes well the game should bypass the startup movies and go straight to the main menu.
Reference: StackExchange Gaming post by xenphilos