Gamer isn't going to win any awards but it's a fairly harmless way to spend 85 minutes. It's essentially a post-apocalyptic grit fest, with a prisoner - wrongly convicted, of course - being used as a pawn in a video game. Cross that with a "Sci Fi for Dummies" story about the corruption of business and the ethics of removing human free will and you've got the movie. It goes over the top - almost constantly - but moves so quickly you won't mind.
You may have noticed I use "-porn" as a suffix to describe a trait taken to excess for gratuitous purposes, such as explosion-porn, shootout-porn, car chase-porn and dismemberment-porn. Gamer is so gratuitous that I lost track of all the "-porn" adjectives I could use to describe the movie. The four above are just the primary ones. You want gratuitous? In one scene, the hero does one of those neck-breaking moves - putting the opponent into a headlock and twisting the head - twice! OK, the bad guy - a death row inmate - had survived a hanging once before so the hero had to be sure, but still.
Gamer liberally cribs from other movies, The Running Man much of the time, Death Race for a while, Road House even. I might have been a little less harsh on the film but near the end, the villain - yes, an overly talkative villain who could easily have killed the hero when he had the chance - does a musical routine to the tune of "I've Got You Under My Skin." Entirely surreal and inappropriate. Nonetheless, because of its brisk pacing, simple plot, and Gerard Butler finally suppressing his Scottish accent, Gamer gets a mild recommendation as a popcorn movie.