French achievement website Succesfull and MyGamerCard have added a new Xbox Live Arcade title that seems to have completely gone under everyone's radar - it seems that a game called Shadow Assault / Tenchu is going to be released for the service.

Now Tenchu has been a long running franchise from FROM Software, still kicking around since the PlayStation days, with Tenchu Z on the Xbox 360 and Tenchu 4 coming to the Wii sometime this year. So what exactly is Shadow Assault?

From the sounds of it it's not just a port of a classic Tenchu. Instead there are several missions - at least 28 of them, which can require you to run around unseen by anyone. There is also battle achievements for racking up a high combo meter.

With the achievements out its now just a matter of time until the game itself is unveiled then.

In other news, they also released the achievements for the ever elusive Beat 'n Groovy game by Konami, which you can check out here. Two games that haven't been unveiled, yet their achievements are out. Looks like we're back to the regularly scheduled program.

Source: Sucessfull.FR, MyGamerCard