Blasphemy! It is a timeless classic that must be revered!
Well, Bloodlines uses a beta version of the Source engine, so you cannot expect it to look as good as a game that used the final version (although it would have been nice if the had used the regular version).
What is your skill level? They can be extremely hard if you haven't invested in the necessary requirements - and, if you have, they are not that hard.
Anyways, Culpa Innata, S.T.A.L.K.E.R., and Bloodlines.