You heard about its existence earlier this week, and Nintendo Power took the liberty of confirming the title yesterday, but today Sega officially-officially unveiled the 3DS relaunch of the Shinobi series. Shinobi is a mix of original 2D side-scrolling gameplay with -- you guessed it! -- 3D occasionally mixed in.

This fall's 3DS title will follow Jiro Musashi, progenitor to the original game's main character, as he "becomes a true ninja legend" in the only way he knows how: "by mastering a brand new combo system switching between melee, ranged, and acrobatic attacks." The true ninja way!

Beyond announcing a September 2011 release window for Shinobi, Sega sent over a mess of new screens and a trailer with gameplay, which we've dropped after the break. Be careful to watch for shurikens as you sneak past the guards!