i like how well you did the big daddy's "rough" design and the Aliens "smooth" design, the only thing about the Xenomorph i don't understand is; is it a queen? if so its too small, a queen would dwarf a big daddy. looks like a small praetorian. i like how you included a pair of little sister eyes in the vent and added some other background things, but my attention is drawn to the tail, nice job capturing the "smooth" part again, but the tail doesn't appear to have any type of bladed edge on it, which is something nearly every xenomorph has.
the colors are nicely done, but it seems a bit TOO bright and colorful for that kind of place in rapture, and threes no visible damage done to the environment considering modern day rapture has water nearly everywhere and debris decorating the place as if it was intended to look like metal Vietnam