Mnementh said:

Some examples that come to mind:

game announcement release sales
Duke Nukem Forever 1997 2011 (14 years later!) > 2M
Final Fantasy XV (originally versus XIII) 2006 2016 (10 years later) > 6.5M
The Last Guardian (project Trico) 2008 2016 (8 years later) > 1.2M
Zelda: Breath of the Wild 2013 2017 (4 years later) > 5.6M so far
Star Citizen 2012 ? (no firm release date yet) not released yet

Seems the sales are mostly fine.

Add Team Fortress 2 to that list.
Announced in 1998 and released in 2007.
I don't have firm numbers for it, since it is F2P.
44 million owners on Steam, and updates over ten years after release: is a success to me.
The game also came out on the Xbox 360 and PS3 via The Orange Box.
http://steamspy.com/app/440

Star Citizen has "sold" over 1.9 million units (1.9 million backers) as of right now.
Almost 176 million USD raised via crowd funding.
https://robertsspaceindustries.com/funding-goals

Also still in development:
Dwarf Fortress, has been in development for over 15 years now.
No release date is in sight.

Last edited by caffeinade - on 03 January 2018