In Juarez, the player selects either Thomas or Ray McCall at the beginning of each level, and the AI plays the role of the other. Although the adventure is heavily scripted in nearly every aspect, their constant company provides ample opportunity for dialogue between the characters. These conversations help build a sense of familiarity with the characters, and it's very welcome to play a game where I don't feel like a lone soldier fighting a war all by myself. Honestly, the back-and-forth between the brothers is the best aspect of the entire game.
In Ghostbusters (I'm still really early in the game) but the first section featured constant chatter between the player and the main characters from the films.
With the exception of two or three extremely brief segments when separated from the rest of the Bustin' crew, the game was very much about a team atmosphere. As a fan, I was extremely thrilled to hear that all of the original actors reprise their roles, but aside from that fact, it was quite enjoyable to (again) not feel like that solo character taking on the world.
I think there's definitely a lot of room for game developers to explore this avenue. After all, gamers have spent so many years being the one who saves the girl/city/planet/universe that I think a title or two putting players in a team, secondary or supporting role would be quite welcome change of pace. The key difference would be the amount of constant interaction the NPCs had, as well as the copious amounts of dialogue. By simply exposing the player's character to the presence of other characters, an entirely new quality begins to emerge thanks to the fact that the talking isn't limited to between-level cut scenes or two talking heads speaking via bubbles.
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