Unecessary backgrounds should be made transparent (per submission rules)
These pieces show promise, but not polish. A bit of advice: slow down a bit. It's often that we get new members, who are new to pixel art, that make lots of small 'quick' pieces, and then they all get rejected, so the artist gets discouraged. At this stage in the game, you should focus your efforts on a single piece, and put a decent amount of time and effort into it to ensure it gets into the gallery. My suggestion would be to take whatever piece you've got that you like best, and make a thread for it in the WIP forum. There, you'll get feedback and critique, which you can then use to improve the piece and make sure you meet gallery standards. Too often new members skip this vital learning stage.
thanks