But really, yeah, some platformers had high scores, especially in the early days (as they mimicked the arcade era that came previously), but are any of them well utilized? In Ikaruga, high scores are garnered via comboing groups of three similarly colored enemies, which leads to extremely complex patterns - never mind dot eatting. People literally play that game daily for years hoping to perfect it. Games like DonPachi require the players to space out each individual kill in such a way that the combo goes higher and higher - space out kills too slowly and the combo dies. Psyvariar 2 involves grazing as close to bullets as possible to gain brief invulnerability and higher scores. In Ketsui, the closer you are to an enemy when killed, the higher the score bonus.
And by scaling difficulty, I meant this:
Sure, most games have scaling difficulty... but not the kind that brings people back to the exact same game daily for years.
An important distinction here is that platformers, by and large, weren't designed for the arcade. Where arcade games had a larger incentive to get the players pumping as many quarters as possible into the game, console games had the incentive to get the players to buy as many games as possible. High scores were tacked onto games like Super Mario Bros. because that's what Nintendo did in arcade games like Donkey Kong before them. The first three Super Mario Bros. games are the hardest in the series and they still don't even approach the difficulty of the average shooter. Shooters have been painstakingly hard since R-Type and Darius and they've only gotten harder. Platformers have gone in the opposite route - they've gotten easier over time to appease the masses. I think homebrew is where the most platforming development has come over the last few years, with games like I Wanna Be the Guy and the brilliant VVVVVV - both of which are extremely hard to master.
As for the decades, I didn't think it was relevant to speak of the exact history of FPS and shooters, when the popularity of said genres came decades later.
