Not spectacular and nothing compared to the rest of the series. Good to play with friends.
The stories have nothing to them. To be honest they are a complete waste of time and unless you feel you need the trophy (like me) I wouldn't bother. It involves you listening to a load of rather annoying dialogue and playing as characters you don't really like. This is the same for both path ways MK or DC and so the story is not much to talk about. For the same reason I won't tell you what it's about because if you do decide to play through them, I don't want to spoil whatever story is worth following.
The practice mode is very helpful although most of the combos and special moves are very similar between characters. Once you have mastered at least one character you can usually pick another quickly with little effort. This was a downside to me as I like to be able to spend a lot of time working on a single character and master them. In general the practice mode is cool but not essential.
There's no need for me to speak about the Vs. mode but the online is the games best feature. Once you select the online mode you are asked to choose a universe. Then you are put into a lobby with text chat and a list of other online players. In this lobby you can select another player and challenge them to a match or you can simply sit and wait for someone to challenge you. You can also view people's statistics which shows their current wins/losses and win streak. Even though the statistics are not complex they are more than sufficient. I find its most fun trying to beat the super human players online with friends.
Overall this game is a lot of fun for a short while, more so with friends in the Vs. or Online modes. I wouldn't advise paying full price for this (£40 or $60) maybe pick it up out of the bargin' bin for at least half that.