I felt like I was watching someone play a first person shooter video game with really long cutscenes which I liked at first. And then I hated it. And then all of a sudden it got really action-packed and gorey and I liked it again. I settled on hating it. The concept of this video-game-as-movie thing seems great at first and then just gets really boring.
However I will say that with a budget so small the gore was pretty decent.
Also, I can't imagine anyone wanting to date that girlfriend. I would have stopped answering my phone.