this is an old arcade game everyone in there 20's must have played it. the mac game is a clone from the taito machine to get the original game with the full 100 levels it also has an original game and power-up secret mode accessed by a button combonation on the title screen. download macmame from here
http://www.macmame.org/downloads.html
which will emulate the arcade machine and get the rom from
http://www.mame.dk/mw.phtml?search=bubble+bobble&w
hat=desc
try the earlier roms first as they are the best if you have any trouble there are a few fan based sites offering tips and advice if you are on a pc (god help you) just go to
http://store.apple.com/Apple/WebObjects/ukstore
only jokeing go to
http://www.mame.net/downmain.html
and get the appropriate .zip if the previous answer already worked dont give this absolute corker of a game the brush of give it a go it wont let you down.