Nah, you didn't mess up. I just want to help you improve this ^^
First off, I would desaturate the colour a bit. Cubone seemed to wanted it like this, but the colour right now looks unnatural and hurts my eyes a bit. So I'd suggest to desaturate it and make it a very little bit darker. You might want to experiment with this a bit.
The second problem is, it looks a bit boring. I have multiple suggestions to fix that. First, you might try changing his pose a bit, maybe make him have a bit of a hunchback (try around with it - it might look good) then, play with the shading and get rid of that pillow-style - it's generally a thing to avoid.
Then, perhaps add some darker features or blend the single blobs into each other to make them look less separated. Last but not least, try making the head less like a perfect circle (again, you'd need to experiment here) and try what it looks like when you move the eyes down one pixel.
That's all I can think of now. It's 3am after all.