i see what your trying to do. and the whole comic book black lines effect your doing is a very retro thing to do. carnivac is the artist that comes to mind when i think of that.
anyway you were looking for feedback. so yeah i think, right now you just need to practice a little more on actually shading your sprites. because honestly right now the lack of detail on the sprites is whats hurting you the most. having a simple style and doing absolutely nothing are two very different things.
looking at my pixeljoint or deviantart galleries might help you a little there. as i have a simplistic style myself. as you said your a programmer not an artist. well we have that in common. put as a programmer i take it your a person of logic right? well look at it this way. say you were learning about something new like some kind of advance collision or something that was totally new to you. well what would you do?
simple, you would do some research. ask around, test and see what works for you. well research should get you enough help to see how people are doing tiles. i recommend looking on pixeljoint. and search for something with a low color count. because thats the stuff thats probably going to help you the most. then look at some tutorials, and you go from there.
you'll find eventually you'll run into a style that works for you. i find 8 bit kind of style fits me the best. i sometimes have to make my own colors but thats what works for me. you might find it the same way. now i took the time to edit your image a little. using the colors you had already used. and i didn't put much work into it. i made one quick and simple change that you'll notice instantly.

see by adding the blackline to seperate the stick and the platform. we give the illusion that the stick isn't fused to the very side of the platform. but is actually positioned somewere in the middle. and as for what i did with the top of the platform, well i think you'll agree that looks good. basically by making the lighter area smaller then the darker area we give the illusion that its actually a floor.
i didn't put much work at all into this, but i think by doing it i might have helped. anyway this took me about a minute to do and that was simply because of how long it took to keep switching between colors and color the lines needed. so hopefully i've been of some help.
Edited by x-death, 29 May 2012 - 11:03 AM.