Awesome job.
Animation/Graphics - This is a really high quality game that you have here. All of the animation was very smooth and drawings were well done. I understand you didn't draw anything more than squares, but everything about the game was good on the eyes. The color used, background, etc...
Story/Content - Not an original idea, but still a very fun game. I personally thought it was a little easy, but that's just me. The only level that I died more than two times on was level 5. I think that might be because it was the first "hard" or different level. After that I knew what to expect though.
I think you can really add to this game and add different shapes. That would bring a lot of different element to the game because trying to aviod a circle and triangle is obviously different from trying to advoid a square every time just because of the shape.
Something else that you may want to think about making for the game in the future is upgrades. Something like having a time for each level and the sooner they finished the level the more money they received. They could then by small upgrades like a shield that takes one hit before it disappears, speed upgrade, maybe a health upgrade so it takes more hits to kill you, etc...
Audio - I thought it was a great choice for audio here. Really fast pace and quick just like the game itself. I don't think it needs any sound effects, but if you do implement the money and store to the game you could add some money sounds and things like that. That's obviously completely up to you though.
Overall - A good game to play and perhaps if it had things like upgrades it could be a little better.
~ Review Request Club ~