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)