Like a true silent assassin, not a lot is known about IO Interactive’s Mini Ninjas. Aside from a rather cute announcement trailer (above, just in case you missed it first time round) and some guff about saving the world, we didn’t have much to go on, story-wise. But as the game starts to gear up for its fall release, Mini Ninjas is slipping out of the shadows.

Here’s what IO Interactive have told us about your adventures as Hiro, the vertically-challenged protagonist: “When the Evil Samurai Warlord, with the help of an ancient magic, turns forest animals in to an army hell bent on world domination, Hiro must lead his small band of Ninjas on an exciting journey through a disintegrating world, to battle the magical hordes of twisted Samurai and eventually confront the Warlord in his Fortress of Doom.”

The journey to the Fortress of Doom will take Hiro and the gang through a variety of environments, from bamboo forests, to snowy mountains, treacherous castle interiors and flooded valleys. Hiro will have to use potions, magic and his ninja powers to defeat evil. IO Interactive warn us to, “Prepare yourself for a Ninja adventure like you have never seen before!” Which is great, but, they had us at “ninjas.”

Mini Ninjas is due for release in fall 2009 for Xbox 360, PlayStation 3, Nintendo Wii, Nintendo DS and PC. Check out our galleries for 18 fresh new screenshots.