Not going over ones others have already mentioned:
TitanFall 2 is an incredible shooter, with really good single player campaign... came out in 2016, and since, though its official servers went down, people figured out how to run private servers and mod the client to work with them, look up Northstar.
Even works on linux, there's a whole entire custom Proton branch just for TitanFall2/NorthStar.
FTL came out in 2012, but the Advanced Edition came out in 2014, maybe that counts?
Stardew Valley came out in 2016.
No Man's Sky came out in 2016.
Alien Isolation came out in 2014.
Undertale, 2015.
Metal Gear Solid V, 2015.
... 2015 +/- 1 was a pretty good era for a lot of pretty great games, imo.