There is nothing too interesting on this.
As like some people said, this is good for wasting time, though it's not a bad game.
But you really should add some other features, just like, Shaders, Text Tool.. And of course, a fulfill-tool .. You know, that bucket tool e.e
Anyway, I'm not saying this is a bad game, but it's not so good.
Hope you can see this review of your game.
Make it shine just like other painting softwares - ( Photoshop, Gimp, Paint.NET, And many others ).