I agree it is an underrated game. It was different than the other star wars games, you got to use a jet pack and your pistols never ran out of ammo. It also has a decent story and it also gives a background story (told in the bonus material) in comic book form. If you take the time to collect the bounties so as to earn the bonus material. Some parts of the game can be frustrating but that is common in all games, some of the bosses take several tries. Although I prefer a check point system to the # of lives based system present in the game. I did however like the unlocking of cooler and better gear, like jet pack rockets and a flamethrower.
I like that it showed how Jango got his gear and what he did before Star Wars II:The Attack of the Clones. I am a star wars fan so of course I liked it but even if you are not a huge fan it can still be enjoyable.