The graphics are adorable. It also makes the grandma standout amongst the cookie muggers, which is useful for tracking her onscreen.
The upgrades are straightforward, as they upgrade the property that's labelled on the button. However, I am uncertain as to what the "Grandma" upgrade actually does. There's still a bit of space on the button, so it may help to have a short sentence on the button as to what the property being upgraded does for the player.
Moving the cookies away from pup-pup is difficult when they get between you and pup-pup because grandma sometimes doesn't phase through the cookies. This results in the grandma pushing the cookie mugger into pup-pup. This doesn't seem like intentional behaviour
Aside from the delivery rate being affect, there doesn't appear to be much of a penalty when the tamales are being stolen from pup-pup. I am curious as to how the muggers getting to pup-pup affects the overall in-game progression