Old School Revival, Old School Renaissance, Old School Revolution, or Old School Reformation.
Games that draws inspiration from the earliest days of tabletop RPGs. Concretely, that inspiration is summed up in the jargon word Appendix N.
'Appendix N' refers to Appendix N of the 1st edition AD&D Dungeon Masters Guide, which listed fiction that was an influence on Dungeons & Dragons.
(Do you play or care about an OSR game? Add it to the list.)