The concept is pretty cool, and I really like the audio and graphics of gbooble :)
Some suggestions would be to add a DontDestroyOnLoad method on the audiomanager as the music restarting every single time I die is a bitfrustrating, and I can't tell if its just or me or that the twitter page seems a little unbeatable (for me)..... The bullet is a little too slow and by the time I wait for the bullet to pass and reach the bottom I can't reach the link anymore :P
Anyways the game is quite interesting, great job!