Feels more like Half Life Alyx would be the killer app for VR instead, but I'm not sure what the replayability is. Maybe with a VR gmod based on it or something?
I wouldn't call it a killer app simply because these days, FPS is all about multiplayer, and a FPS multiplayer in VR is just...meh? It doesn't really work.
Really, any sort of action-packed combat is just not going to work in VR. Jumping behind cover works fine outside VR because the medium acknowledges the limitation. But in VR, trying to jump behind cover doesn't work when you have to worry about being next to the edge of your play space. VR tries to immerse you, but that immersion is limited when you can't touch your surroundings. Being crouched behind cover and peeking over it to shoot feels unnatural and immersion-breaking when you can't lean against the wall you're hiding behind.
Even as a VR supporter and owner of a Valve Index (And the HTC Vive before that), I don't know what the killer app for VR would be. To be honest, I'm not sure I'd even EXPECT there to be a true single "killer app" for VR, but rather, a collection of apps that work incredibly well in VR, or don't work without VR. Beat Saber comes up a lot, and it's fun, but I wouldn't call it the "killer app". It's just an example of something that only works in VR.
Super Hot manages to pull off immersive combat in VR like to other game, it’s absolutely fantastic - but it only works for this particular type of game mechanic.
Beat Saber is the most successful successor to DDR. DDR worked without VR obviously, but requires an expensive and easy to break input device. Also, downstairs neighbors are less likely to complain when you are playing BeatSaber vs DDR.
I played Alyx some and it was neat, but I didn't get terribly far into it as it wasn't very compelling for me. Maybe because I've never played the other Half Life games?
From having friends try different things in VR, Beat Saber has been far and away the biggest hit with the most people relative to any other type of game or experience.
Out of ~20 people, I think there has only been one who liked something else better (the X-wing mission in SW:Battlefront).
