Popeye and Tintin have entered the public domain [for the US, other nations may have different rules], so I'll just go ahead and start the countdown clock for our first Sailor Man soulslike
Any spinach-fueled super strength might have to wait a couple more years, though.
Different laws may apply world wide. Ie: in Europe is not about the publication date, but author life-span (author's works get in public domain 70 years it's death: TinTin gets in PD in EU in the 2054)
Yeah I’m guessing you can retell “in the land of the soviets” if you wanted and use Tintin’s design from those first strips, but every other story is likely still off-limits. Would have to be a completely original story using the character.
And some of the favorites like Captain Haddock, etc, weren’t in Soviets.