Although the release of the "Saw: The Video Game" (Spaceballs the Flamethrower?) is months away, IGN recently posted this video preview that finally offers a little more insight into the general makeup of the game.
Basically, it appears that there will be some action parts to augment the puzzles, which I think was a concession to keep casual fans from being really burnt out on traps. As far as those go, I think the mechanic of digging into a toilet full of hypodermic needles or someone's insides looks to be handled pretty well, assuming you don't have to do it every five minutes. Although it seems to be a relatively faithful representation of the films, I'm not seeing anything that screams "must buy" yet, but to be honest "Saw" related properties just aren't that interesting or exciting to me anymore.