Arcade: Ultimate Mortal Kombat 3

Xbox Live Members can now download ‘Ultimate Mortal Kombat 3’ demo from the Xbox Live Arcade. The full version of the game can be purchased for 800 points.

Here are some game details:

Enter the world of ULTIMATE Mortal Kombat 3 and discover 22 playable characters, classic fatalities, brutalities, friendships and babalities with tons of environments, and multiplayer Kombat Mode as you fight to defeat Shao Kahn!

Players can choose from 22 fighters with different abilities. You also have secret methods to allow playing additional fighters. 
Classic Fatalities, Brutalities, Friendships and Babalities!  Finish Him!
2 on 2 kombat mode
Tons of environments to fight in including: Scorpion's Lair, Jade's Desert, Kahn's Kave, River Kombat, Noob's Dorfen and more.
Each character, has their own good or evil motives and a common goal. THE DESTRUCTION OF SHAO KAHN!
A variety of multiplayer modes including the new Challenger Versus Mode which allows you and 3 other friends to battle it out in a "winner-stays-on" style tournament.
Detailed Leaderboards:  Captures the player's win and losses both for all time and for the current week.  
Challenger Versus Mode:  A new multiplayer mode which allows up to 4 players to play in a "winner-stays-on" style tournament.  Statistics are recorded to allow for maximum bragging rights!
12 achievements:  The UMK3 achievements offer rewards for both the novice and expert players.

Edit: Not sure why it's not showing up in the usual place, but go to Arcade-> Genre ->Coin op Classics.

Edit: Some folks can't see it…I am escalating