It's not going to win Game of the Year, but it deserves better than the poor reviews it has received from most sites.
There are better pure pinball games available for the GBA (and now DS with the recent release of Metroid Prime Pinball) but this game can be very appealing to Pac-Man fans and nostalgia buffs. The two tables are enjoyable (four if you count the day/night changes of the existing two), the sounds are great (fruit, ghosts, and various other sound effects from the Pac-Man universe), and the side goals are fun to work towards on each table.
This game does what it needs to do for Pac-Man fans that want to enjoy playing pinball in small spurts. Don't let the overly harsh reviews keep you from at least playing the game if not buying it from your local bargain bin.