Hi Exequiel
Is that your first name? If not, could you please put your first name in your profile?
I'm afraid there are several problems with this shot.
Composition - Generally, it lacks an interesting focal point to draw the eye. The low wall running up the centre just divides the shot into two halves.
Image quality - 30secs is a long exposure. You need to get more of a mixture of light and dark throughout the shot when shooting at this time of day. The bottom half is just about there, but the top area of lights on the horizon are just burnt out. Here is an example of a shot where there is a better spread of light (he is not a member here)
http://www.flickr.com/photos/yury-pr...ko/3925889894/
I don't know the geography of the place but you might have been better moving down to the end of the walk-way and just shooting the lights on the other side of the water. I think your exposure would have been more balanced.