Personally, I'd recommend using far less colours (limit yourself to 10, for instance). Use a middle-tone background for your sprites (I use semi-strong sea-blue), since it'll make contrast flaws more evident. Etc. Etc.
There are plenty of pixel tutorials around the net.
Heres some good advice; when you need to make tiles, like your grass, or a walkway or something, make it as hard as you can to tell where the edges of the square are. Put some features like a bump that goes off the right side of the image, and then create the end of it on the left side exactly lined up. Basically make alot of things that don't just exist in the middle of your tile, but on the edges and going all around the sides, lining up with the opposite. This way, when you put tile it side by side with itself, it doesn't look like a whole bunch of squares, but rather a single smooth backdrop
are we perhaps, missing the point and he's really being sarcastic?
(With the truth being, DC graphics suck, which is hardly not the case.)
(lame attempt in my viewpoint, perhaps i'm being sarcastic, oh well.)
(in which case, i apologize, im not really sure what to say at all)
All platforming problems can be mostly solved here: