Kenryoku_Maxis on 16 February 2010
First time I played it, I think it took me about 70 hours just following the story and doing some exploring. However, second time I played it, I did everything possible including all side quests, exploring all areas, getting all GFs, etc and it took me about 80 hours.
Still my favorite Final Fantasy.
Six upcoming games you should look into:
Essay Pro