Thanks for your contribution! However, the method of saving progress may not be future proof for adding or removing extra saved settings. What I’d recommend is using a BMessage and the “Flatten” function to save it into a BFile. (There’s documentation at https://www.haiku-os.org/docs/api/. You’ll want to look in the Application Kit section for BMessage and the Storage Kit section for BFile)

OK, I'll remake it

Like this?

This looks better, however there are a few more things to note:

It's done but I've used AddUInt32 (not AddInt32 like you said), because fBoard and fPreviousBoard are uint32_t arrays

That’s a whoops on me. Either way, this looks all good to me! Let me get @mmuman to take a look at this to actually get your changes approved.

Great! Thanks for help!

Maybe "Haiku2048_state" would be a nicer name than just "Save". Otherwise it seems to work fine after having a quick play.

And the coding style doesn't fit to the rest, which at first glance looks like Haiku's coding style. Compare curly brackets and spaces etc.