Every pixel was placed by hand of course
I have a very hard time believing this, as it looks like not a single one was. It would sure be interesting to see your reference image.
Additionally, there are
44 colors including some semi-transparency, where there should be 5 including full transp.
Sorry but I can't say much except start again. Pick a reasonable size for hand pixelling (100x100
max), a 4-color palette (you can adjust that later, no need for precision at this point), and before that do
a lot of reading-up through these forums to understand what pixel art is (and what it isn't).
