“When you make a movie, always try to discover what the theme of the movie is in one or two words. Every time I made a film, I always knew what I thought the theme was, the core, in one word. In The Godfather, it was succession. In The Conversation, it was privacy. In Apocalypse, it was morality.”

— Francis Ford Coppola

I've always liked this approach to screenwriting: reduce the story's central theme to one word. In relation to Palm Springs, here's my one-word take: Connection.

At the beginning of the story, Nyles has zero connection to anything. He lives - and relives - each day where there are quite literally no consequences Why? Because when he wakes up, he's opens his eyes to the same day again... and again... and again. It's all meaningless, so, hey, let's just get fucked up and do shit. He's a nihilist, a cynic. He has no authentic connection to anything other than living with the meaninglessness of existence.

Enter Sarah. Here the "movie gods" throw Nyles a curveball: You're going to have a partner on your journey. Sarah, a newbie to repetitive time loop living, is in a different psychological space than Nyles. Perhaps if the roles were reversed, *she* would be the cynic and Nyles would be the idealist. But the fact is she has far fewer experiences reliving the same day, thus, she works her way through the equivalent of the Five Stages of Grief. She has not lost contact with what it means to be a human being: meaningful connection. Not just to another person, but the past and the future. Check out this scene which happens in the first half of Act Two.

https://www.youtube.com/watch?v=kVhaNSWb5g4

As noted in previous comments, what Nyles discovers is a connection to Sarah. And she to him. Through her desire to escape the loop - and him eventually overcoming his fears of what life will be like *outside* the loop - they escape. Together. They have found a connection and that - metaphorically - is what empowers their escape.

In that regard, Palm Springs is similar to Groundhog Day: Phil finds a connection with Rita and that empowers him to change (ethically) which is what enables him to escape the loop (as compared to Sarah's scientific plan). But the connection theme is the same in both stories.

Central theme: Connection. I think that works for both Palm Springs and Groundhog Day.