We've noticed something interesting about the two expansions available. They're both complete games in their own right; or they can be combined with the original game, or each other.
Ascension: Return of the Fallen "is playable as a 2 player stand-alone game, or can be combined with Ascension: Chronicle of the Godslayer for an expanded game with up to six players"
Ascension: Storm of Souls "A complete 1-4 player game playable on its own or with other Ascension games! Combine with other Ascension games to play with up to 6 players!"