From ebgames.com:

Based on the DC Comics/Vertigo Hellblazer graphic novels and with all the supernatural thrills of the highly anticipated Warner Bros. Pictures film, this action horror game literally takes you to Hell and back! You are cast as irreverent mystic detective John Constantine and must embark on an investigation in a world of demons and angels that exists just beneath the landscape of contemporary Los Angeles. Caught up in a series of catastrophic events, it is imperative that you seek out and destroy pure evil - before peace on Earth is destroyed forever!