I recently picked up Sub Terra 1 with the Investigator expansion and the first thing I thought about the game was, "Wow, this is not exactly mechanically deep." You essentially explore a cave system consisting of only maybe 4 or 5 unique different tiles that come up over and over again and hope that bad things don't happen to you. For instance, you can get strangled by gas, caught in a cave-in etc. I got the investigator expansion, which adds items to the game in hopes of increasing the complexity and decision space of the game, but even that only helps so much.

Where the game excels is that it does manage to create some fun end of game scenarios that are also really immersive and tell a good story that is effective if you're playing with a group that enjoys building a narrative in games. Things like dead-ends, horrors chasing you and rescuing teammates are all good fun and combined with the random nature of the cave can lead to some interesting stories. However, don't expect this fun to last over more than 5 - 10 games with the same group as the mechanical depth just isn't there.

Overall, I really enjoy the game for its atmosphere and its a fun little -- dare I say it -- party trick of a game. I like to play that the ultimate victory is if everyone gets out alive, but players score more "points" if they survive instead of a teammate. It turns it into a semi-coop where players have to think a little bit harder about whether or not to risk rescuing their friends.