I think both Killzone and Ryse are more or less tech demos for their respective consoles, I played through Killzone, liked it, but it's not going to warrant a replay... so I traded it in while it's still worth something to get credits for my copy of Infamous:SS... in the mean time I took advantage of the specials Target offers here, 35$ for most PS4 games... I got Knack and Battlefield 4, both will keep me busy until I either get Infamous or Tomb Raider...
Outlast will get some play time as well as I am on PS+