Congratulations on finishing your first game! It's functional, I suppose, but not really much more than that. Having to change needles to pop different kinds of balloons is a neat idea, but it's really difficult to tell what needle you have and when it's changed, since it's not in your control and there's no kind of feedback. I'd imagine that this game is nearly impossible if you're colourblind.
Here's a little tip: try not to convey information in games through colour alone. Have the needle make a sound when it changes colour. Give the balloons different patterns. Stuff like that will make your game so much more palatable.