Conegamer on 15 May 2013
Probably Luigi's Mansion. Let's say it ends up around the 3mil mark.
The Vita's best selling game will likely be Final Fantasy X and X-2, with around 500k each on average. So 1mil for 2 games (pretty positive).
Killzone should sell around 450k, Assassin's Creed around the same. Then maybe Soul Sacrifice will hit 400k. But that's only making it 2.3mil, so even upping everything by 100k won't allow it to beat Luigi.
