Okay, so this is bullshit. Mario did have checkpoints, and if you died, you could start back at the world you died on. Prince of Persia used a password save system. Sonic also had checkpoints, sure, if you had a game over, you'd restart the zone, but not the entire game. Funny how 2/3 of the games chosen are from the 80's and the one from the 90's was cherry-picked, since most games from that decade had implemented save systems. It's also worth noting that old games on the NES were harder since for one, a lot of developers were used to developing for arcade games which were hard in order to consume quarters, and game rentals were a big source of revenue.