CMC Alien Force

Sorry for double-posting. I'm posting this separately because I'm looking for some critique and advice. This didn't turn out quite how I wanted, but I don't know why.

I was attempting to mimic the composition and tone of this old piece of Chrono Trigger art: [link] . That is why most of the outlines are still black and I limited myself to (mostly) just cel shading. But after playing around with colors and various little details I couldn't get it to feel right.

I'm looking for help to understand what I did wrong. I've spent too long on this piece, so I probably won't be trying to fix it anymore, but I'd like to learn from this so I can apply it to the future.

Any feedback you can give would be greatly appreciated.

(download for bigger)