The ESRB reports that this game contains: Blood, Use of Alcohol, Violence
Parents should be aware of the bloody nature of the combat and the sexually revealing nature of the graphics for the female character and NPCs. The 'Use of Alcohol' warning is probably because of one specific example of obviously irresponsible drinking, but it is presented in such an obviously comical sense that I hesitate to validate it as a serious concern. If you're only looking for an innovative and ground-breaking gaming experience, then Dark Alliance is best avoided.
Fans of the PC Baldur's Gate series should rent and see if the transition from turn-based strategy to real-time hack-and-slash action works for them.
Fans of arcade action games like Gauntlet should give it a look, although a rental is still probably in order due to the short length of the game. For those of us who are addicted to the 'let's go shopping while busting heads' dungeon-crawl gameplay made popular by Diablo and the roguelikes, Dark Alliance makes a good case as the game to have for the PlayStation 2, despite its many shortcomings.