Mortal Kombat Outworld Assassins is a fan made game based on Mortal Kombat Mythologies: Sub-Zero game, but with a lot of fan made plot stuff.

In this game you play as Sub-Zero, Scorpion or Noob Saibot, and it's a prequel story, that tells the origin of those 3 characters before the tournament. And like i said above, the story is fan made, and thus everything that you see here is made up.

The gameplay is basically in beat'em up style, where you running around different locations, beating up bad guys and fighting with bosses. But, there is some extra stuff to it, like you can use some super moves and special moves, and also you can do a fatalities on bosses and enemies when they are low on health. But you can check that out in "How to play" option in the game itself.