For MK I don't think the wins is all online (I'd have to check to verify). I think there's a trophy for 100 wins online but the wins for mastering a character can be offline.
But even considering 350 hours, a VAST MAJORITY of that time can be accomplished while you sleep, so I'd have to agree with Kylie that time shouldn't be a huge factor here. The game will still take time, just not as much as it sounds.
To me there's still difficulty like the no continues on hardest mode, which even my friend was complaining about, and probably some of the online stuff since connectivty is kinda spotty. The challenge tower was pretty easy. I only skipped 3 missions because I was annoyed and I suck, but I can see them being doable.
I'd probably have to say 3 stars if I had to vote. 4 might be possible but pushing it, and definitely not 5.
