In the first, you control 3 characters, and switch between them, which is alright, but it's a bit buggy sometimes, still a nice introduction to dungeoneering.
In the second, you first play as the leader of a team of 4, killing enemies, then you play a grieving enemy... in a very, very twisted storyline, with your dead brother's ghost telling you to kill the characters you once played... you have to play it to experience the disturbing effect.
In the 3rd, you play a very overpowered enemy, for some good enemy killing fun. :) Also got a nice option at the end, when choosing what to use my xp on:
