R* not mentioning PC ;A;.

Mafia III: I really regret choosing to buy this over Rise of the Tomb Raider. Plan on selling it when I finish it.

Mirror's Edge Catalyst: This game was not meant to have an open world. It just ruins the experience.

Uncharted 4: No, this is not a bad game, but I haven't played many new games this year, and I just didn't end up liking U4 as much as any of the PS3 games. That said, it stands as my GotY, though FF XV could beat it.

1. Dirt Rally. After all the hype on PC it was a big letdown, mainly due to bad controller support and little content.
2. PS4 Pro not having a dedicated PSVR port.
3. NS reveal. Not worth delaying Zelda for.

This year was pretty disappointing until PSVR came out. I have bought and played more games on PSVR than in the last 6 months.

Bernie Sanders not being the Democratic nominee

And no Persona 5 until next year

God I hope they do it. Miss MP3 so much. 

Good question.

If this was 2015 I could lay out a bunch. But 2016 has been pretty good to me.

3) DOOM - the campaign ended up being OK, but hardly as transcendent as earlier games. And multiplayer was a bore.
2) PS+ - just a bad year overall for Sony's "free" games line-up. 
1) TMNT: Mutants in Manhattan - I love me some Turtles co-op brawling, but this title was just so anemic.

But...

This has been a year full of happy surprises too!

5) Pokken Tournament - never expected a Pokemon brawler to be one of the best fighters of the gen
4) Song of the Deep - Insomniac struck gold with this ingenious "Metroidvania"
3) RIVE - Two Tribes triumphant farewell is a twin stick shooter for the ages
2) Gears of War 4 - I've spent all gen doubting MS' first-party studios, but The Coalition proved me wrong
1) Severed - the best game of the year is a first-person dungeon crawler on PSV, 3DS, and WiiU? Color me surprised.

Honestly simply put No Man Sky is the only game that has undelivered for me, namely that time has passed now.

No Man Sky (This turned out horribly).

Still no mention of Star Citizen actually release date (getting tired honestly).

Recore (wasted potential that didn't live up to MY hype).

No Man's Sky

I've not bought anything else I was let down by. However going by reviews and what some gamers have said I'll add Mafia 3 and Star Fox Zero to the list.

Zelda being delayed to 2017

The Switch being delayed to March

No Man's Sky