This is probaly the most compelling game I have played so far in my 10 years of gaming. So far I have about 40 hours into this game and I am still not close to having everything unlocked, or every character maxed out.
This game starts out with the main character waking up from a 2 year nap. I will not go any further into the story so it will not be ruined for you. The story is very funny at most if not all times. Its a very light story nothing to be taken seriously like FFX.
The graphics are on par with about FFT, but after playing it you wont really care. It is more of cartoonish graphics then real ones.
Sound is also very good. The voice work is quite well done, and entertaining. Battle sounds are also well done.
The replay value is insane. 9 999 levels to get your characters up to, you can level up your weapons in the item world and find new items all the time. There are multiple endings, and after you beat the game you can restart with your created characters. You can only get the story characters when you would get them in the story. You can reset you levels back to one and get stat bonuses using the dark assembly. The dark assembly is a place when you can pass bills to unlock new levels or get better items at the shop or stronger enemies.
Overall you should get this game. Don't rent it just buy it if you can find it in stores it is getting harder and harder to find.