Halo 3 - Xbox 360 (Microsoft) - 3.3 millionHow do you explain the Halo 5 drop then? Going from 3m+ in a month to a bit over 1m is huge. Plus, Halo didn't do as well on XB as it did on 360.
It did that in 8 days.
Halo 4 (360) - 3.2 million
This was like 24 days.
Halo Reach (360) - 3.3 million
This was about 16 days.
I am not really sure that the platform matters that much.
The people that are generally the more enthusiastic will certainly have an Xbox One.
New dev could mean disaster, I do agree.
I don't expect Gears to drop as much but it will drop quite a bit.