The best way to sum them, up - the good, the bad, and the stupid. The aliens are very well animated and it was nice to see they all had their own unique way of 'dying', instead of all just blinking and disappearing. It's apparent that a lot of work went into death animations (which also makes me question why - but that's between the animators and their shrinks). Unfortunately, the same can't be said about agents J and K. One of the things that makes the MiB license work, besides the cool guns and aliens, is the conflicting personalities of the two main agents, and it would have been nice if this could have been conveyed in the game. I would have liked to see the cocky swagger of J or the strict cadence of K; instead, I was given two pallet-swapped corpses. I may be asking for too much, but after seeing how great the aliens looked or the little detail animations (such as your agent being knocked back after shooting the Noisy Cricket), I just felt let down.
Like the graphics, the sound is okay, but nothing to make you regret playing with the sound turned off. The level music and effects are standard fare for an action game, but they're done well enough that they never get annoying.