You left in some of MSpaint's default colors.
Anyways, I'm gonna be blunt- the selout looks terrible. On such small sprites you're probably best off not having an outline.
I made a little edit of the reaper fellow:

Mostly just showing a different approach. Of course, your flatshaded style got lost in the progress. But, yeah, just 'cause your sprites are cartoony doesn't mean they shouldn't have shadows or highlights. And the reaper light grey on the reaper is pretty redundant (you can hardly see it, you could have just use the blue on the scythe...)
Yeah, I dunno how to end this post, so... uhh...