I recommend that you pop over to Steam and spend £4 to get a fantastic game while it's 2/3 off!
I just spent half an hour playing the entry level of Mark Of The Ninja, and it was great fun. Very nice "hiding in the shadows" gameplay, very fluid, lovely graphics, and seamlessly put together. Frankly, you can't spend £4 on anything better today!
Original post on Dreamwidth - there are comments there.
- So, you've always wanted to be a Ninja...