My movie philosophy: don't blame a movie for not being what it's not meant to be.
To enjoy a movie, you don't need the movie to be amazing, great, or even good (sometimes). You just need to know what you should expect.
So what do you expect from gamer? If you want gore, violence, blood, nudity...go ahead and see it. If you want Gerald Butler running around shooting people, fighting people, baring his muscles and looking tough like action heroes do, go ahead and see it. If you want Michael C. Hall playing an evil guy trying to take over the world, and baring his muscles, and even showing off his Broadway background a little bit, go ahead and see it. (but you'd be a little disappointed since he shows up less than you'd expect as this is quite a short movie, only 1.5 hours). Even if you want to see some hot lesbian actions probably imagined by very non-lesbian people, or a cute teenage boy who probably isn't supposed to do anything other than being a cute teenage boy...go ahead and see it.
But If you want go in and find some surprise- and twist-filled plot, some complicated multi-layer character development, or some brilliant insight into society or even humanity, then no, don't go see Gamer.
The problem is, if you are really expecting the later things I mentioned, I think it's partially you fault that you are going to spend one and a half hour of your precious time sitting in a theater suffering from this movie and then hate it with a passion. Because really, those aren't what Gamer is meant to be, even though some people may actually believe that they are.
The reality is that while not what many would call a great (or even good) movie, Gamer could be thoroughly enjoyed, as long as you know what it should be. Because I think it's everything it set out to be. You just need to (maybe grudgingly) accept what it's supposed to be and either enjoy it for what it is, or realize that it's not a movie for your high level of intelligence and ignore it completely.