Probably the best Tenchu yet, and this review is from December 2007.
Tenchu was always a ninja-simulator based on feudal Japan, and with a heavy emphasis on eliminating or bypassing your enemies without being detected. This was pretty much a pioneer for the Stealth Action genre, when Tenchu: Stealth Assassins was released in 1998 in the US. Although a previous version was met with a Japan only release in 1997, Stealth Assassins was just an update to that title.
Despite the ordering of the games, Tenchu: Wrath of Heaven is actually a direct sequel to Tenchu: Stealth Assassins. Tenchu 2 was a prequel to these games. Ok, now for the review.
This game does away with a few things and adds a few to the table. The Mission Builder from Tenchu 2 is gone, unfortunately. A lot of the items we saw in previous games are gone, but there are new ones that either do the same thing or something different now. You can't swim at all like in Tenchu 2, and you can't sheath your sword or drag bodies out of the way either. The removal of these definitely drops the score a bit, but nothing major.
The controls have been redefined, so no more Resident Evil-esque controls. The controls are analog based and 360 degrees, making combat and sneaking around much easier. The horrible draw distance is gone too, and you can see pretty much the entire level if at the right angle. This greatly improves gameplay.
You can now gain abilities by filling up the "Kuji" meter, which consists of 9 unlit Kanji. Each stealth kill fills up a Kanji, while killing innocents resets the meter all the way back to emptiness. The more Kanji you have, the more powerful your attacks get, so it's wise to kill at least 9 people to have a better chance with the bosses.
The abilities themselves range from useless to extremely helpful, so it's a good idea to unlock them all for each character. You play as Rikimaru, Ayame, and a third character named Tesshu, who is unlocked when you beat both of the other Ninja's modes. While he isn't a ninja, his is a doctor by day and an assassin by night, but only kills if it serves justice. His kills will remind you of a feudal-japan version of Manhunt, since he has some of the most brutal kills in the game thanks to his knowledge of anatomy and such.
The graphics are pretty sharp, with nice lighting effects, very good particle effects, some nice bloom in some places, and overall the game just looks damn good. The animations are equally as good, as are the voice acting and sounds. It's a really good game to look at and hear.
Unfortunately, some things have been ignored apparently. The enemy A.I. can cheat sometimes, but is overall dumb as ever. I really don't understand why almost every game these days suffer from dumb-brained AI. Enemies, after they spot you, give chase for about 10 seconds then just give up and act like nothing happened. If you kill, like 2 enemies in an area, and a 3rd guard comes up, he will get excited and go into search mode, then go back to normal mode, then look at the OTHER body and do the exact same thing. It's really embarrassing seeing this, and watching things like enemies walking into pitfalls and into solid walls.
The game also has a new 2 player mode, which supports split-screen co-op and versus. Co-op lets you use the 3 characters from story mode while Vs. lets you use most characters from the story mode. It's fun but the lack of customization and maps really makes it get old fast. It's also offline only on the PS2 version, which is a shame.
The game has nice replay value too, with 3 enemy/item layouts for each mission, for all 3 characters, and 3 difficulty levels. There's tons of bonus content to unlock, secret combos, etc.
Overall, I recommend the game. It gets an 8.5 from me.