We have just released (15) Steam Trading Cards for Mortal Kombat 1, along with associated Community items (6 Badges, 5 Emoticons and 3 Backgrounds). Note that on top of MK1 players being able to earn some of the Cards by playing MK1, users can trade with other players for these items, buy items off the Steam Community Market, buy Backgrounds or Emoticons through the Steam Point Shop, or trade with other players which is now made easier via the Trading Forum.
For more information visit the Steam Trading Cards FAQ:
• https://steamcommunity.com/tradingcards/faq/