I really don't think it will.
It's been a long time since KH2. They lost their momentum a long time ago.
Also, it's gonna sell on Xbox about as much as FF does. Wich is not very much (about 1/5th).
Kingdom Hearts 1.5+2.5 & 2.8, collections that were released after FF XV (Xbox One at 1.07m), are outselling it 1.29m and 1.09m (VGC numbers, but the series went from 22 million shipped to 24m in 2017 via SE Press site), respectively. 1.5+2.5 is a rerelease of its PS3 versions that also sold over 1.25m (VGC numbers), so its not a good look for FF XV (Xbox) at all. Plus, KH has never outsold FF, so those KH3 Xbox numbers, I can only see it at ~500k LTD. That's pocket change to SE.
Just looking at previous sales (according to the numbers on this site).
The first Kingdom Hearts was the most popular, but they are roughly in the same ballpark on the other games. I think I've got to give it to KH3, but it would be pretty close.
Except that GoW will easily beat the other games of the series by far (already above 3M, surely around 4M?). For now, I don't see KH3 doing a lot more than the previous one. The story seems so complicated and impossible to understand for new players, that I'm not sure it can expand its players base. And it doesn't have that much hype for now either...
So far, I'll go with GoW. Even with One and Switch.
Before I say what I'm going to say... Are you comparing GoW with handheld games or the GoW series)? Need an answer before I continue.
The story is complicated and impossible ehgegdkdgkdj? That's irrelevant. KH3 Co-director Tai Yasue stated in 2016 after E3 that Xbox gamers (and newcomers) can play KH3 just for the gameplay and Disney worlds. Plus, every relevant KH game has explained the past games in the character journal
Also, if they care about story then they can buy KH 1.5+2.5 & 2.8 on PS4 as Tetsuya Nomura planned in 2012 when he decided to create KH3 to unite the scattered games onto one platform so fans can play the story before KH3. That's called recultivation.
Anyway, KH3 will not outsell GoW as a PS4 exclusive. I see up it to 5 million max on PS4. Xbox One version is pocket change (around ~500k LTD) so its not a difference maker to even mention regardless.
Last edited by Rob5VGC - on 04 May 2018