Hi everybody, I'm new here. I've recently decided to try and learn to create pixel art that I could use in games (I'm a programmer), and spent the whole day working on my first piece. I'd be grateful for any tips and advice regarding:
1) how to improve the piece
2) ideas for the piece (it's pretty plain at the moment and I'm not sure what I could add to it)
3) anything else that comes to mind, really. I'm open for any comments

What I'm trying to create is a dungeon-prison type of environment that some vampire could have created below his castle in Überwald.

I looked at the cobblestones from
http://www.pixeljoint.com/pixelart/48487.htm when drawing mine, so they're similar. I dunno if that's maybe frowned upon in this community, so I wanted to be upfront about it (I didn't copy or trace them, though. Just browsed the gallery for ideas). I used some random photos from Google for the wall bricks and wooden texture