Only Bugsnax for now though, right? And then Worms Rumble on December 1. Unfortunately, you need access to a PS5 to add the PS Plus Collection games. But when they're added, you can play them on PS4 as well. I've checked and it works.
Oh so you MUST have a PS5 to play the PS4 Collection games... interesting :o Oh well, I've literally got every game on the list already anyway lol :P