It's fine. A bit on the boring side, but it's about average for a Battle Network game. The biggest problem is that the main plot of the game is a tournament-arc, so you're forced to do the daily whatever and then you'll return to fight the associated boss in the tournament setting. It's not really bad, just kind of mediocre.

The real problem is if you want to 100% the game, because then you need to replay it three times. And here's where the real problem comes up: Along with the regular mainline stories, there are six "tournament" stories and each playthru you'll see three of them. Not a huge deal with the first playthru. However, you're guaranteed to replay one of those in the second playthru and you'll have to replay two of them in the third playthru. So if you're trying to 100% the game, you'll end up not only replaying the regular story content repeatedly, but also replaying the same tournament arcs over and over again. It gets pretty old pretty fast, especially compared to MMBN3 which just had additional content at the end of the game.

There's also a concern if you're trying to grab a specific soul, because it might not actually show up until the end of the third playthru. So you're more likely to not bother trying to hope for a specific one. (even if some are ridiculously good)