One of the biggest problems with Horizon: Zero Dawn was that there wasn't enough of it. But don't worry, an expansion is coming.
In an announcement on the Guerrilla Games website, the developers announced that the studio is "already hard at work on an expansion to the story", although no specifics or time was given. The studio did add that Horizon sold more than 2.6 million units digitally and on Blu-Ray, which hopefully means we see more Horizon and less Killzone in the years ahead.
If you haven't played Horizon already, small tip: you really should. It's one of the few games that really showcases the power of the PS4 Pro, regardless of whether your TV can do 4K or not. The photo mode is also great to mess around with, and the art is top notch too.