First off, I really enjoyed this game. I'm not sure what it is, but there's a certain charm that hooked me on playing right until the end. That said, the game is VERY simple in nature. Although it DOES suffer from repetitive gameplay, I didn't find this to be a crippling flaw. I was perfectly content with playing the same level 40 or 50 times, because seeing Bieber "backwards age" was utterly satisfying in and of itself.
The real thorn in this lion's paw is the audio. Just after hitting play it became apparent to me that your microphone is not up to snuff. The speech seemed muffled and suffered from background noise which made it hard to hear some parts of the dialogue. My recommendation: buy a better mic. I'm sure that you're a fine voice actor, but the rubbish audio is holding you back. I should also point out the lack of variety in sound clips. After a while I got tired of hearing "damn pedophile!" and "we love you Bieber!" I'm pretty sure the police only had two sound clips associated with them and when you die (or become incapacitated), there's only one phrase Bieber has to offer. Perhaps the introduction of more sound clips would have improved this. After all, for such a long game, you're going to hear a lot of the same thing.
I really liked the art style of this game, although I would have liked to have seen a bigger variety in characters or "props." Playing the same level 50 times isn't very exciting to the general population (I didn't mind it, but...) so maybe a change in setting every once in a while would improve the game's dynamics. Nothing HUGE is needed, just maybe place the rubbish bin or hydrant box in a new location. This could add both variety and a new challenge to the player as he/she attempts to navigate around more (or less) obstacles. I get that the concept called for a single park to be the setting for all these harassments but variety could have improved the game.
I should also note that, much to the contrary of other reviewers, I DIDN'T mind the ads. They don't seem as in your face as other reviewers claim. I respect the fact that you're trying to make some cash off your game, and so you should have that right. The ads didn't break the game for me. However, I didn't really find the "bonus videos" to be all that entertaining. Frankly, I didn't watch any of them the whole way through. Definitely something that could have been omitted. Also, it's a nitpicky thing, but the font selection was not fantastic. I would have went with a more bold font on the upgrades menu. It just makes things easier on the eyes.
Overall, I really liked this game. Don't look at all my criticisms and think that I hated this game, I actually loved it. It was fun and held my interest right up until the end. The fact that you can continue playing after you've become 16 again is kind of pointless, but hell, I still loved it. Good job mate! I'm looking forward to more from you guys!