You don't have to actually "hide" anywhere; instead the enemies all display a certain field of vision, and as long as you don't step inside it, you're okay.
Ahh, so it's like a regular Tenchu game. *rimshot*
I'm definitely gonna try out the demo when I get my 360 back this weekend. I wish a good Tenchu game would come out...I was able to enjoy Wrath of Heaven, but that was when I was more innocent about game quality. They need one that totally rips off MGS, but with a ninja skin.

What I mean is, there's no standing up against walls, crouching to avoid being seen, grappling to a higher area, that kind of thing. I get a bit of a Trap Gunner vibe from it.
With Tenchu, my favorites are:
-Tenchu Shinobi Gaisen (PSone) (This is the U.S. version back in Japanese, with a level editor and bonus level)
-Tenchu Shinobi Hyakusen (PSone) (Stand-alone expansion to Sinobi Gaisen with 100 fan-made levels and the level editor)
-Tenchu Fatal Shadows (PS2) (Still have yet to beat this actually...enjoyed what I played though)
-Tenchu Shinobi Taizen (PSP) (K2's best Tenchu game, awful draw distance aside, it rocked)
I played through all of Tenchu 2 too, but spent far more time in the level editor than with the actual game. Looking forward to Tenchu 4 on Wii; it's only a few weeks away in J-Land.