Mortal Kombat for the Vita is a rare complete port of the original that adds even more value.
First off, I'm happy to say that all of the original gameplay is here. Every character, fatality, stage, mode, and features from the console versions have been ported. This is an important thing to mention. Quite often console ports to handheld games strip out things in order to fit on the smaller format. A good example is Tekken 6 from PS3 to PSP strips out the Scenario mode in order to fit the entire roster on it.
The controls for the Vita are pretty tight, but can get cramped because of it. I found the D-pad not quite as responsive as the DualShock controller for the console. However, I still was able to pull off moves 95% of the time. Occasionally, I had issues doing an uppercut because the D-pad wasn't able to register fast enough. Otherwise, the controls work as they do on the console versions.
It is worth mentioning the additional controls and features that the Vita version packs. In addition to everything that the console version had including all of the DLC characters and Kratos, the Vita version of the game includes 16 new costumes for the characters (including new ones for the DLC characters), a new 150 level challenge tower, touch based fighting and fatalities, and Test Your Slice and Balance mini games.
The new challenge tower has some very interesting levels that really take advantage of the Vita's controls. Aside from the Slice and Balance mini games interspersed throughout, you get to fight as Shao Khan at times, wipe blood from the screen while fighting, tilt and shake the Vita during fights, and a host of other neat ideas. The challenge tower is how you unlock the 16 additional costumes, but it doesn't feel like a burden since many of the levels are very fun and challenging, rather than frustrating.
The touch based fighting and fatality controls aren't exactly my cup of tea though. They aren't bad nor do they feel tacked on, they just are. I found doing touch based fatalities to be a bit harder than just inputting the commands with the buttons. Also, your move list doesn't tell you how to do them which is kinda silly.
Visually, it's definitely been scaled back. All of the fighters have a much expectantly lowered polygon count, but they do run at 60 fps. So while the characters don't look as good up close, they run butter smooth. However, the characters still look decent when pulled back during fighting. The effect is most jarring, however, when playing the Story mode. During the Story mode, they recycled the in-game engine cutscenes from the console versions. While this looks great, you're suddenly presented with a drastically lowered character model when the fight starts. It's not horrible by any means, but it does look a bit odd.
The backgrounds for MK Vita are surprisingly animated. Ultimate Marvel Vs. Capcom 3 stripped much of the background movement in order to focus on the characters, but Mortal Kombat retains considerable action. There have been a few things removed, but it's hardly noticable.
I do have some issues with the sound. While every sound and voice is intact from the console versions, I found the sound to be too low. Even with the Vita at full volume and the game set to full volume, I was forced to turn on the subtitles in order to hear dialog.
There's an amazing amount of value here. It's surprising all of the things that were in the console version made it along with entirely new content. The $40 price tag might be considered double dipping to some who already own the console, but I felt it was worth it considering what was added.
Mortal Kombat for the Vita is a triumph for handhelds. It breaks the mold of the handhelds receiving stripped down ports of the original. Indeed, MK Vita gives you everything the console had including the long Story mode and adds some unique Vita-centric features worthy of purchase.
The Good: Smooth gameplay, all characters and modes present from the console version, additional mini games and challenge towers for value, new Vita control features are fun, fighting Shao Khan feels much more balanced.
The Bad: Visuals have taken a small hit in order to make it onto the Vita, sound is far too low for my liking, lacks crossplay with the PS3, online only over Wi-Fi.