A certain afford has been given in this game because graphic has it's simplistic yet intelligent style.
There is little above the standard. Game is short - only 4 levels. Music is dull but acceptable.
There are major design flaws. After getting + the ball will be added at full speed. The first bounce is difficult so your extra ball usually makes its first and last swing. Balls can bounce of each other. What seems like interesting feature quite often results in ball going horizontal (first time have I seen such a thing in this type of game).
Overall: 2 for being decent but repetitive. +0.5 for effort.