Very cute game and concept, I like the final message.
Really, some small nitpicks, the movement is not super satisfying because there is a big difference of speed on x and y axis.
I think it would have been better if the player character changed size uniformly, just have your jump height change and not the x-axis speed was a bit weird.
The player should move faster on x-axis, or you should just be able to jump by keeping the space key pressed and the more people you gather the longer you can keep the key pressed to jump higher or something.
This is the only "issue" I had, but really, the game itself is nice with its message.