I think the ending was satisfying in that the way everybody acted is based on things we already know. Yuuki is bitter at the third wolf, jaded by having to kill so many people, and short-tempered, so we can at least imagine her throwing the game. My biggest regret with this series is that we never get to see the MC confront the fact that her and her crush surviving are mutually exclusive. It's not like she'd just realize, "Oh, my main goal for this game is impossible", it'd just be a question of whether she decides to sacrifice herself for him, or commit a "lovers' suicide" by killing him in the game, then herself once she won, or killing him and justify it to herself by saying he'd forever be with her in spirit. Instead, the ending isn't really up to her, and she just compartmentalizes it by deciding he wasn't really like her dad.
Though I think the conclusion to her romantic obsession was satisfying. She fell in love with him because he resembled her dad, but all she really wanted was someone who was there and would love her. Once he couldn't do that, she stopped loving him.