This is a fun simple game I found on reddit.
Here's how you play it:
What you are trying to do is fill up most of the screen with the round balloons, as shown here:
You click and hold in the game area to create a balloon. As long as you hold down on the mouse click, the balloon will get bigger. Don't let the red balls touch your balloons while you're inflating them. If they do, the balloon will pop and you will lose one life.