SUPERHOT: MIND CONTROL DELETE will be granted to all existing owners of SUPERHOT on Steam, Epic Games Store, GOG and Origin. The only requirement to get a free copy of MIND CONTROL DELETE is to own a purchased copy or purchase SUPERHOT game before 16th of July 2020.
After the release, SUPERHOT: MIND CONTROL DELETE will be added automatically to your Steam / GOG / Epic Games Store library. If you own a SUPERHOT game on Origin, you need to send an receipt to freemcdfororigin[at]superhotgame.com for an activation key.
People who acquired copy of SUPERHOT as part of free game giveaway at Epic Games Store, Twitch Prime or Game Pass are not eligible for a free copy of MIND CONTROL DELETE.
Source: Official SUPERHOT website.