Did you know there are 119 games in the Mario franchise, 109 for Mega Man in some form or another, and 43 in the Dragon Quest wheelhouse?
Needless to say with sequels, remakes, and spin-offs of those numbers, franchises can often reuse the same ideas. And with reason, of course: a lot of those ideas are good ones.
Do you know how many games are in the Alpha Protocol, LA Noire, or Middle Earth franchises? Yeah, not many, but each of those games had a fantastic element that could have been used ad nauseum like so many other mechanics.
And yet, for whatever reason, they were forgotten.
The Nemesis system, first person view in a sports game, your friends controlling AI - some of these things were lauded in terrible games, some of them derided in great games, and some of them a mixture of either.
Let's discuss when the game industry came up with some really interesting mechanics - then just tossed them in the bin like a bunch of used tissues.
10. Nemesis System - Middle-Earth: Shadow Of War
Middle-Earth: Shadow of War is a disappointing game. The story is garbage, the fighting system is passable at its finest moments, and the whole thing is just a slog of 'meh'. Except for the Nemesis system, which has some really interesting mechanics to it - it's really just a shame it had to be part of something so lacklustre.
When Shadow of War was first coming out, the Nemesis System was so lauded for its ingenuity that there was a fear it would become the new 'cover based shooting' of games - being force-fed into every upcoming product for the next decade. But in the end, not a single major release has even attempted to recreate the system.
Now technically Warner Brothers owns the trademark to the name Nemesis System, but you can't copywrite an idea. There's no reason not to make a similar idea - even if its only parts of the system.
Can you imagine Borderlands with some strong bandits as your rivals with your after-death revival being the New-U feature? Maybe GTA with whatever cop or opposing gangster who 'wasted' you getting a promotion and receiving rewards for getting vengeance on them. Or what about Assassin's Creed, but your targets are dynamically created in-world instead of being scripted enemies and a glitch in the Animus causes them to grow stronger upon your defeat?
So many untapped possibilities!