Ace Attorney (a.k.a. Phoenix Wright)

It peaked in the first trilogy. Each game built on what was good about the previous game while adding a new mechanism that flashed out another part of the game.

The second trilogy of games collapsed trying to follow it up. Both the writing and gameplay show the same issue. The games are trying to be a clean break with new characters and powers but the game designers were afraid that they might scare away fans of previous games, so the old characters and gameplay all come back to make an appearance. None of it works. The returning characters and gameplay are all very brief and shallow without the progression they got in their original games, but they take up so much space that the new characters and mechanics don't have room to build up over the course of 4-5 cases in a game.

I am now trudging through the two prequel games. The game designers finally had the determination to make a clean break, but it seems that they lost the magic of the initial games. There are new characters and new gameplay. There is too much plot, not enough game. There is too much (bad) writing between player interactions and when they happen, the game is more hand holdy to make sure the player is given a bucket of clues about what to do next. And there is no reason to make the game easier, since there is a new easy mode that plays the game for a player if they ever get stuck.