In some games, nailing the stealth sweet spot is like trying to hit a hummingbird with a throwing star. If enemies are too tenacious, sneak-and-strangle missions devolve into trial-and-error pandemonium. But in Tenchu Z's case, the bad-guy AI swings too far in the other direction. Samurai sentries have the memory of a calculator watch. When caught in mid-creep, an assassin just needs to roll around a corner or slither into a conveniently spacious crevice in a nearby wall and wait. Within seconds, the rent-a-ronin go back to their rounds, practically inviting players to insert katanas between their vertebrae.
There's something to be said for this kind of zero-resistance game design. Silently subduing and snuffing evil henchman can be immensely satisfying. The fact that they're easy pickings means that there's less friction between players and their gruesome goal. To make up for this ease, there are 50 missions, which would grow tiresome were the game's stalking grounds less lovingly rendered. Period villages, castles, and harbor towns make excellent ninja playgrounds. Nimbly leaping from wall to wall and creeping across ornate rooftops by the light of the full moon is a hoot. Tenchu isn't a total pushover, though: The guards are as thick as a sack of sumos, but every so often, players will encounter a vigilant mongrel or a noisy rooster that will raise the alarm.