Promo pack given out at Essen Spiel 2018 with purchase of the 8Bit Box system.
Pack also found in December 2018 issue of Tabletop Gaming.
Comprised of 3 "Cheat Code" cards, 1 each for Pixoid, Outspeed, and Stadium, these cheat codes allow you a special surprise ability if your recent plays have matched the required sequence on the card in order to gain a bonus.