The game has a nice level of polish, but I was disappointed that objects outside of the bubble were still interactive. Would have been cool to turn off collision for platforms outside the bubble. The precision jumping made the game a little too artificially difficult for me, but I can see how others would enjoy.
I have an idea for further development though.
The Bubble starts at a certain size. It starts shrinking slowly right away. You have to collect objects to increase the size of the bubble and keep it from shrinking entirely. This could add an element of urgency to the game.