I still fire up my copy now and then. It's good for nostalgia, though it aged kind of poorly even compared to similar games.
I only boot it up like once every 3 years. I do listen to the soundtrack regularly. I do love the game despite barely playing it. It's a game that changes your life but the game itself has low replay value. Which is why I like the fan-games and game development just to see new things.
I myself "replay" YN every month.
Replay as in, just chill out while watching the scenery.
Same for .flow.
I do this but only 2kki. Shit feels weird when things like that colorful sky world thing I got used to changed some time after to some grungy desolated scene.
For YN I just fire up OSTs on youtube or something. I lost my save ages ago and don't really want to repeat it all again.