What's the criteria for changing HN post titles?

The earlier posting was 'A marriage proposal hidden across two playstation games' or something like that.

Is there a HN bot doing this or is it the mods?

Yes, we changed it in keeping with https://news.ycombinator.com/newsguidelines.html: "Please use the original title, unless it is misleading or linkbait; don't editorialize."

In this case, though, "Under the microscope: NCAA Basketball Final Four 97 (PlayStation)" didn't seem right, so I used language from the opening paragraph instead. That's one valid place to look, when scouring a page for representative language suitable as a title.

https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...

It's the hard suffering mods.