i can see inprovements
the game right now is dull. add music. maybe something fun or i dont know really. make modes. time mode, story mode, and survival.
survival, is much like what you have now. you have x amount of lives and you need to catch burgers.
time is basically see how many burgers you can catch in a certain time limit.
story is basically a combo of both. your some dude who work at burgerstick or something punny. the restaurant explodes due to a terrorist attack. burgers explode in sections( this gives you levels.) you start off easy with just catching burgers. then add lives, time etc.
i hope this can help. i also hope you take at least 1 of these ideas into consideration, and also a highscore table.