You may not want to hear this but you kind of have to learn EVERY character in the game to some extent... just so you know high's low's mediums' special high's(that hit crouching block but not naked crouch.) and special medium (hit's naked+blocking crouch, but doesn't break crouching block)
I might have the special names backwards oh well. Point is, You need to learn like every character... just to know how to beat them.
Mortal Kombat is not a game you can pick up and just jump online. You have to do alot of memorizing/learning before you can compete.
Smash brothers/Blazblue You can generally easily link things together as long as you know the basics. Easy to pick up hard to master games.
Mortal kombat is not that easy to just pick up, considering you have to know the entire cast and what they are capable of. that was a large gripe between some of my friends wanting to pick this up. That they have to sit there for hours just to learn the normals.