Thank you all for you suggestions, I'm definitely going to fix these errors when I am able

(My computer is at my fathers house, therefore only weekend use, yo)

Its a good piece but the main issue is the lack of contrast, between the yellow of the eyes and the skin mostly, some more contrast could be cool also in some other place, like the nose...

Try making the mouse's outline a dark grey only 1 pixel width (not one long line), and add contrast to the yellow part of the eyes (in relation to the white fur).

the font and general outline is terrible D:

you didnt need to use that many colors

Some color and anatomy issues. And as Basil said it is messy.

Around the pink part, right? And thank you♥

It's a bit messy. You should probably add anti-aliasing.