Man, dumb that detail down. Simply simply simplify. Rid the dither noise. The color yellow doesn't say "rock" to me. Even the texture doesn't say rock. This does not rock. Create some telltale rock formations. Mind your lightsource. Let's see a little shadow casting, not just arbitrary highlights peppered throughout.
Always hard to judge game tiles outa context of their intended game's environment. . .
Don't posted scaled versions. Here, in this site, you just click images to enlarge by 100% increments. CTRL+click to reduce.