LogFAQs > #966545597

4 just barely has the original formula intact

After that, you got like 7 which is parts Survivor, parts Dead Aim, parts modern horror formula. 6 is a movie. 5 is Gears of War. 8 is set up like a Metroidvania and to reflect aspects of a sandbox crawl thru a haunted castle. REm2ke hiccups trying to mend the gap. And even then, 4 goes way into MGS & DMC territory throughout the game. There's a merchant and a Napoleon clone and in-game mini-games.

Originally though, the story and art picked up where the gameplay and graphics left off, but this isn't really the case anymore. RE3 and REmake/zero were probably the last true RE games.