Monster Con: Cthulhu Pack is a standalone expansion for Monster Con that works with the original game but does not require it. Below is my review of the original but it is entirely applicable for this standalone expansion.
I was fortunate enough to have the game's designer (Lester Smith) teach me how to play this game at Con on the Cob 2013. What I like about Monster Con is that the rules are very easy to explain to new players. The simple trick-taking mechanic is easy to pick up for anyone that has played traditional card games like Hearts or Euchre but the thematic elements and new mechanics like the monster abilities are engaging. I find this is great gateway game, particularly for groups of people with varying levels of affinity for specialist games.