Nice little toy, funny and stylish character design and artworks, the voice acting is also very funny, and the game is already a nice to play distraction.
Right now, obviously, there is no purpose to the money you make, it's just a click and hold to play the game, and that's fine as it is as a concept.
However, I feel like you could do a bit more with the gane by making a very simple change: make it a local 1v1 mini game, where you play against a friend to see who can sell the most balloons in a certain time limit maybe. The change is quite simple, you add another stand on the right, and makd the game play with the keyboard (use 2 different keys to inflate the balloon), and could make for a little fun minigame to play with a friend.
Also, even though the artstyle is part of the fun and style of the game, I'd suggest you not to scale the sprites of the stand too much, maybe keep everything at the same scalr so that the outlines of the sprites are not incontinent.
Other than this little adjustment, I think the game is very nice as it is already, good job!