The game is made more varied by the fact that races and special powers are dealt from separate decks - you might find yourself with Flying Ghouls in one game and Diplomat Ghouls in another.
Each player can play more than one race in the course of the game. One of the most critical decisions facing a player is when to put a race into decline and start a new one.
There are many expansions available, some have tags here at Board and Card Games:
See also: vinci, which this game re-implements.