I agree with Sideburns that the photo is just bleh, because of the lack of vibrant colors, but about it being underexposed, as pointed out by LaFoto, I'm gonna have to disagree. I think this exposure is good because it creates the silhouette effect as seen in the foreground element, by the way, thank you for using a foreground element! A lot of people don't utilize a foreground in landscape shots, but it's almost a must-have to me. Anyways, I like the exposure because of the silhouette effect, but the colors, yeah, they are just too dull. And Sideburns is right, the shot is a bit crooked, that's an easy enough fix though. And also, although I don't think it kilt the shot because of your utilization of a foreground element, but be wary of splitting the shot in half with the horizon, that can be a very risky composition.