So how to add a video like this for your game?

Install Fraps or your favorite game screen recording tool.

Install VirtualDub

Open and edit your video in VirtualDub

Add filters: Menu/Video/Filters/Add… and add the select 2:1 reduction (high quality) twice to create a video with quarter of the size

Change framerate: Menu/Video/Frame rate/Change frame rate to 25 fps

File/Export/Animated gif, select target, and choose ‘Infinite loop’.

You’re all set! Don’t forget to rate my game SLICK LICKER!