simple but cool! i like the pixel art for the rats, its very charming c:
the mayor and king rat seem to be swapped as i went from merchant to mayor, which skipped over the king's slot :0 that slot then unlocked next
for some constructive criticism, i would suggest having it so you can click & drag over rats to send up multiple at a time, to make it less click intensive! plus perhaps automatically spawning a rat every now and then?
but that aside i did have fun :D i enjoy the concept of levitating rats into the stratosphere hehe, and the detail of their silhouette behind the podium was a nice touch! great job :D