What to do about evolution cards that don't work well in solo games?
Several cards can be left out of the solo game, as they only have an effect when there are multiple players:


King
Queen
Thief
Spy
Pirate


The main problem with this is that this could change the balance of the game due to the backs of these cards (during crisis).  A middle ground may be to remove them and replace them with the next card when they are placed face up (but disregard the new crisis now showing).

Also, the designer has mentioned (although I can't find it anywhere) that the assassin should not be allowed to kill off your own character cards.