Square Enix is planning to make a big Final Fantasy XIII announcement tomorrow at 3.30pm GMT.

But already may of been detailed by Famitsu, which has revealed details of the new character growth system, along with Hope's summon and of course the loveable chocobo, everyone start playing the song in your head.

According to the Japanese magazine (partially translated by IGN), FFXIII uses something called the Crystarium system, which the website compares to Final Fantasy X's Sphere system.

The idea is that you gather Crystal Points after battles, and these can be used to progress across a chart, selecting which "role" you want for your character. As you improve in this role, you can move onto more advanced Crystarium charts.

Variety will come from choosing different routes across the charts, with progress capped by your overall "Crystarium Level".

Hopefully they will say with the Sphere Grid idea, rather than FF12's licence grid which was ulimately useless and boring but however we'll soon get a clear idea by the Japanese PlayStation 3 version, since it's out on 17th December. Slightly easier to understand is the fact that Hope's summon is Alexander, a giant who either punches enemies or, in his Gestalt form, transforms into a fortress and bombards them with cannon fire.

Then there are the chocobos. According to IGN's read of the Famitsu piece, there's your standard Cocoon chocobo (cute, farmy) and the wilder Pulse chocobo, which you can ride around the world at high speed, at least until its health bar has been depleted by stampeding past too many monsters.

As well as being able to hoist you into new areas thanks to its powerful jump, the Pulse chocobo will be able to sense nearby buried treasure, a bit like Peter Molyneux's dog, although a bit more dispensable.