The blue backlight is cool, reminds me of owlboy or snake's art style in general.
Definitely watch for banding though, you've got it all over and it adds an undesiredable blur effect
Some examples in red here; but there's plenty more:
https://dl.dropbox.com/s/mkz1zv4tg9m952h/banding4.gif
And a quick example of how you might go about fixing the banding:
https://dl.dropbox.com/s/v6olzdwspowry9k/banding5.gif
Essentially you want to break up the clusters so they aren't exactly hugging and creating the blur/staircase effect. In this case I've trimmed them a bit so that they appear as anti-aliasing (smoothed out but still sharp)
Related thread: https://pixelation.org/index.php?topic=8110.20
Should have posted it in its entirety instead of just one piece! thats my only feedback, it looks super good just want to see the rest of it!
I definitely love the backlight! It adds a great contrast and adds a nice sensation of depth.
As much as I like the cliff side, though, the bridge adds a strange problem to the piece perspective. My eyes see the bridge being sideways, but the cliff it is connected to shows part of its top (at least that is what it seems to me). I believe your piece could benefit wonders if you could work on this disparity. But please take my comment with a grain of salt, I am not that experienced/knowledgeable about art/pixel art :)
I would love to see the large picture eventually!