Almost every single last case in any Phoenix Wright game is pretty sad. You don't get a truly happy ending, but instead, you end up re-opening past wounds and learning the bitter background of everyone involved. The "special case" of the first Phoenix Wright (The one where you're with Emma, not Maya) had Edgeworth resigning at the very end, while a bunch of characters such as the cowboy and Emma's sister are jailed. Even though everyone cheers in the end, well, it's not that happy.
I would not say that almost every single case in the Ace Attorney series are sad. I think that the only cases that have that sad feeling are the final cases, 4th case in T&T. That is just me of course. JFA had among the worst cases in the series, they made me happy when I finished them (except the final case).
When you are talking about Phoenix Wright, are you including Apollo Justice?
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