The sound effects in Mortal Kombat are what sell the brutality to me. This can primarily be attributed to the less than impressive visuals in the Vita version. It's not a komplete mess, but kompared to the kalibre of the home konsole versions' display, it just doesn't kut it. Luckily enough, the X-Ray moves and Fatalities krunch and squelch just how I think they should, and I still snicker after seeing most stomach-turning attacks for the fiftieth time.
I feel enlightened now. If you want any further Mortal Kombat flavoured lols, check out this brilliant piece from Samir Torres and Jason Lomberg of Bitmob fame.