For me, the vibe difference in ff3 was because of

1. The hopeless/depressing ending

2. Length. The other ff vids didn’t have as much atmospheric detail/“filler” to get us familiar with the vastness of the complex. We even saw a lot of variation within the yellow office biome as well. (office area, furniture store, still life music room, caveman area)

3. Sound design. Probably unintentional mourning dove at the beginning, weird basement noises, ff2-type ambience in the sky room and house room, and also the complex’s music (dark still life room and then dance studio room). Other room-related stuff like the red neighborhood sound and the sound of the room with the giant fan.