So finally completed this recently. Had my £30 worth of fun I would say.
Zack's voice gets better as you play on. It is weird because at the start I am not sure if it even is the same voice actor as that was terrible. Not sure when the change occurs, but I think it is not long after and then the voice is fine.
In the end this game was designed for the PSP and the lack of openworld shows. The story missions have nice story but the 10 chapters would be over pretty quickly unless you do missions.
The bulk of my fun came from the materia system and finding and upgrading stuff.
Not sure if I will be replaying it anytime soon. But still a must have for a Final Fantasy 7 fan and am glad I have it in my steam collection