Mechanically speaking, this is a very solid and well designed game. The small nature of the party and scope of the game means that the systems that do exist are all able to interact with each other in a lot of interesting ways, creating lots of opportunity for strategy and build variety even throughout a single playthrough. The equipment and insanity skills in particular are favorites of mine; the equipment is designed in such a way that most of it encourages a specific playstyle, and the ever-changing nature of equipment means that this system actively encourages you to change your builds around frequently. The insanity skills are similarly fun, as the random and unpredictable nature of them encourage on-the-fly strategizing and improvisation, meaning combat will rarely get stale.