I saw this on PixelJoint and thought it was a good "first" piece (I saw that you'd described it more as the first polished piece). I hadn't commented over there because I wanted to post some small crits.
There's a lot to like about this. I think some of the details you've put in there are really good. I particularly like the visible roof beams and the chainlink fence. The sofa and TV on the deck is also a nice detail that adds the feeling of a story to the image. These aren't just random items, but people live (or have lived) in this world.
This is a bit of a dirty edit because the main shadow is done with transparency, but that was because I'm not experienced enough to recolour all of the grass and ground texture. The other shadows should all be using the same palette though. I started using the transparency everywhere for speed, and then filled in the easier areas, so forgive me if some have slipped through.
I haven't touched much but I thought the scene would look more interesting with more dramatic lighting. I've moved the sun round to the top right so the shadow are cast into the scene and just worked from there. The house and the deck were shaded in your original image, but the blocks, sofa and TV were all looking flat. I also brought the shadows in at the edges of the roof beams just to suggest they were sitting below the tiles.
I wasn't sure about the light outlines around the TV and the sofa, so I made them consistent with the dark outlines elsewhere. I think that makes them look more a part of the scene.
As far as the edit goes, that's about it: a bit more depth and volume to the scene to make it pop a bit more.
Other things that I think would elevate it further are having a more distinct roof tile texture (at the moment, they're the same as the bricks only smaller) and tidying the grass up a bit. I don't have the expertise to advise you there, but it's currently a little noisy. I know it's possible to render unkempt, long grass in a more controlled fashion and that it's not very helpful to just say to do that, but that's the best I've got.
It would look nice to have a grass texture applied to the whole ground with the longer tufts coming out of it. You could also rough up the edges of the path that leads to the stairs to show nature encroaching.
Hopefully some of that is helpful, even if it's just seeing another person's thought process about the same piece. I'm looking forward to your next picture!
EDIT: Nearly forgot to say but, rather than uploading the image as an attachment, it's easier for us to view it if you host it elsewhere (Imgur is pretty much standard round these parts) because the forum has a built-in zoom function. Clicking zooms on and ctrl-clicking zooms out. You can embed an image by clicking the little Mona Lisa image when you're typing up a post and then pasting in the image location
