Hi, I just played a tie game. However, my opponent won the game but I had more keys, or I don't know what is the tie breaker since it says that there isn't in the rules.
If you go to the game results page for a tied game, you’ll see that there is a score between parentheses, and an asterisk explaining it. This is the tie-breaker for that game.
In case of Castle Combo, the tie breaker is non-stored gold at the end of the game. It is (imo, poorly) indicated in the rules in the endgame section: gold which isn’t stored on cards is worth 0 point, but you still keep it to break ties.
I could’ve sworn I read that number of keys is the tie breaker but same happened to me. I lost but had more keys. Pretty sure the comment about keys is on the rules on this game on bga.