Really hard! Really fast! No kidding!
If you are brave enough, TRY IT!!!
When you try it, you are gonna feel "hard game" experience.
You play as bubble that dodges another bubbles at high speed.
Everything depends on you. How fast is your reaction?
Its not easy. You wont be able to stop. You will try it again and again.
Get an adrenaline rush from the game and improve your reaction!