chris0409 on 24 November 2015
1. Being an exclusive on Xbox One just isn't the same as being an exclusive on Xbox or Xbox 360.
2. Making a game that satisfies an extremely diverse community (that gets more fanatic and diverse after every installment) while still being accessible to newcomers is a hard job, especially when you have strong competition.
3. Halo sales stopped growing after Halo 3 even though the 360 was selling increasingly well.
Taking that into consideration, Halo 5 sales are actually not that surprising.
