#1 the tilt of the horizon's too much, and it's slightly over-exposed.
#2 the image and colors look nice.. feels like a group shot where the back row stands and the front row squats. nice perspective i feel.
#3 i think there's a little handshake involved. it would look more interesting with a fisheye lens
#4 your horizon's slanted, and the buildings on the left abruptly chopped off.
the thing i feel about your images is that there's no subject, and no composition.
except #2 they just feel like normal snapshots.
but don't worry! keep shooting! but do read up on composition techniques and how to correctly expose your images by playing with your settings. good luck