Most disappointing game of 2015, sales-wise?

[JamesGoblin]

JRPGfan said:
Rise of the Tomb Raider?

Even if world wide, with 360+XB1, physical + digital downloads, it has hit 1m,
I think most people thought way back that it would sell more.

My first thought as well, underwhelming sales (of a very good game IMO...blame FO4 "overlapping"), to put it mildly.