I figured out how you can get the "striking girl" achievement:
If there is a group of enemies, attack all, but one with your ranged weapon of choice, then press space.
This cancels the combat and you can target the last one with hand-to-hand.
This should give you 20 (or 21, I think i miscounted) stealth kills for the achievement.
noticed a bug. when you pax often enough so that both players don't have any cards anymore, the pax stacks get reshuffled and players are dealt new cards. Then another pax is called and the opponent plays with his cards revealed (except one in my case). then the game simply stops and you cant do anything anymore.
 "Deadly Venom"){kind=icon}
 "Bird Pax"){kind=icon}
 "Flood Fill"){kind=icon}
 "Epic war"){kind=icon}