I don't think any Square-Enix fan should be disappointed. This game is great, especially for a laugh.
Personally, real-time battle systems are my favorite. So I was definitely enjoyed the battles in the game. Thankfully, the boss fights were rather challenging and not too easy. Having 177 playable characters was certainly an interesting feature, however, I can't see the point in it. There is no way anyone would want to use all of them. During the course of the game, I only used about 12 different characters.
My favorite part of the game was the characters' voices. In my opinion, the voice-overs were perfect. They brought out each character's personality very well. There are also plenty of funny lines that just wouldn't be the same without the voice to go with them. Unfortunately, the battle voices did get kind of annoying after a while.
Anyway, this game is a "must have" for any Square-Enix fan. It's definitely worth the purchase.