***1. Darth Vader, Star Wars The Force Unleashed.*** At the very beginning of the game, rather then your main character, Starkiller, you get to play as Darth Vader himself. Invading the planet Kashyyyk, he seeks to find and kill a lone Jedi Knight. Ensuing a level were your march towards your location, decimating enemies in your way, and having a showdown with said Jedi. And after doing so, Vader finds the Jedi's son, and takes him in. Who is the main protagonist we take control of for the rest of the game.

  
**2. Venom, Spider-Man 2.** A bit later into the game, Peter tries to convince his friend that they have to destroy Venom, which Harry refuses, since Venom was keeping him alive. Eventually, Venom breaks free and becomes one with Harry again. And when it seems like we are about to have a boss fight with him, his father Norman comes in distracting Spider-Man, which causes him to get thrown to the wall. Then, the cutscene shifts to Venom's POV as Norman demands his troops gets the creature off of his son. Ensuing a playable level where you mainly just fuck everything up in that building, then end the level killing Kraven in a showdown.

  
Both of these examples are really awesome and I posted this on here hoping there are more similar examples in games. I personally think both of these games did a very good job at this, and I wish there was more tropes like this in games that pull it off this well. I also just noticed these two examples go hand in hand and have similarities too... man I love badass villains lol.

[Loved Trope] (SPOILERS) A character other then the protagonist gets their own playable level.