This was really fun! It got super frantic but felt very skill-dependant and I definitely got better everytime I played. I really enjoy the simplicity of the challenge and the freeze mechanic once I figured it out added a lot of strategy to it.
I think the game is really fun as is, and if you wanted to polish it some more I'd only really be looking for a bit more sound and animation, even if it's just fades and bounces! I'd love to get a bit more reaction to plopping on a new scoop of icecream, giving the customer their cone, or the customers popping up in the first place. More idle movement on screen would make it feel more alive.
UI was all great and pretty self-explanatory. Really good job!