Aaa they look so CUuute <3
The facial expressions and the postures are nice! When I look at the piece for some time, the characters seem to "fall off" the background, though. They seem like stickers that kinda lack a visual connection to the ground they stick to... Did you try out other backgrounds?
I actually had a thick white outline around them at first -- an actual sticker look -- but decided it was a bit too tacky. This was just quick doodle I did for my friend either way!