Oh my goodness! I have also been on the hunt for the same thing. I was thinking - great idea. Why don’t I find a kids adventure game with dialogue in Portuguese … nope. If they exist it seems near impossible to search for them because surprise surprise all search engines are dominated by Portuguese - BR results.
I tried searching by language in steam, but they have two choices for language search - Portuguese (yes, just portuguese), and Portuguese- Brazil … so you guessed it, if the game has a Brazil Portuguese language option, developers tick both language categories. Oh dear. Out of luck again.
Anyone else had any luck with finding games with PT-PT dialogue or narration? If I find any I will add them to this list.