I bought this during its $5 Steam sale, and I still think it wasn't a particularly good purchase.
I don't understand why people are praising the dialogue. Is it because it's decent by mainstream FPS standards and people are comparing it to the rest of the genre? It certainly doesn't hold up otherwise.
My real problems, though, relate to the gameplay. The Skillshot system had potential, but was hamstrung by the rest of the game. For example, having scarce/expensive ammo makes sense for a lot of games, but in Bulletstorm it penalizes risk-taking and experimentation, something that's important to get Skillshots. I didn't like how lots of Skillshots were tied to specific, small chunks of levels, too. It reduced the options available to the player and once again made experimentation difficult.
There were lots of other little things I also disliked. The many enemies that were immune to your energy lash thing, boring weapon upgrades, the giant dino robot section, and others I can't remember at the moment. Ultimately I gave up on the game about 2/3 of the way through. Without the (very flawed) Skillshot system, the game just wasn't doing anything especially fresh or especially well.