Filling games are one of the old game archetypes. I play tens of games where you need to fill some percent of the level on many platforms: from mobile phones toDS.

Filler is not so special, but like another similar games in this genre is very addictive and fun (for couple of minutes minimal).

Your objective is fill 2/3 of level by balls which grow until you release the mouse button. There is also small balls and if this hits you, you lose a live. You can also kill this bouncing ball by drop your ball to him, butunfortunately it will appear again. And you can also lock these bouncing balls like me on the screenshots.

I must recommend to try this game. You can find it on Kongregate.