Changing up a certain dynamic is often a key element of video game design as a franchise goes on. When Metroid Prime 4 got some more in-depth trailers, it was revealed that Samus Aran would meet up with and work alongside some soldiers from the Galactic Federation, all of whom had been transported to an alien world known as Viewros. As I noted in my review, I thought the soldiers were great additions and added new dynamics to help expand the game’s story and view on the situation.
Others didn’t agree with my assessment and wondered why Nintendo thought about doing this in the first place. The answer came from a chat with Famitsu, where a rep from the company noted:
“When we design games, often we will start with deciding what kind of themes we want players to experience. Normally when players finish a game, they push the A button without any uncertainty, but with Metroid Prime 4 we wanted to make them hesitate and feel conflicted. In order to do that we also have the Galactic Federation soldiers being moved to Planet Viewros.”
Another key element for them was to have the soldiers have key personality traits so you would feel more connected to them, and even protect them when the time came:
“That came first, and then the next step was how the soldiers would act in the game in order for it to feel realistic. Rather than deciding the individual elements to include, we instead decided on the NPC AI and the way they act in cutscenes etc. and from that we would then have the player feel a certain way. “
While I won’t spoil the fate of these soldiers, it’s clear Nintendo had a goal in mind with them, and they could come back…
Source: Famitsu

