Despite never playing MK I gambled and picked it up soon after it's release. I must say it is a brilliant game. A very well made story allows newcomers to the MK series understand who's who and each chapter focuses on a different character allowing you to experience multiple fighters.
The challenge tower offers 300 challenges ranging from killing x amount of enemies before they reach you, defeating an opponent within a time limit, having to 'test your might' and many more.
Online is enjoyable, especially king of the hill allowing you to watch and rate matches until your time to fight arrives. There are tons of unlocks to be had using 'Kurrency' and the classic arcade ladder mode ensures plenty to do.