I've never played Tenchu before, but from playing this game, its made me an instant tenchu fan.
The gameplay is very versatile as there is always a different ways to kill and complete the mission. Depending on the rank and points you get at the end, you gain gold to spend on your character. You can buy alot of things for you character, its split up into 3 categories: skills/abilities; items; clothing. Clothing is very fun to customise, because you unlock them as you play the game. there are over 4 sets of clothing so it takes long to acquire.
However the only bad things i see in this game are the graphics could be... alot better( looks like ps2 graphics ) and maybe a storyline along with some side quests, not side quests along with a storyline.