I’ve been going out of my way lately to find unique mechanics, UI’s, etc. that fundamentally alter and improve a game, to the extent that their removal would severely hurt the game and make it less effective/impactful/etc. To be clear this is less “unplayable,” so not something silly like “removing the right thumb stick from Halo.”
Instead, I think of how Immortality essentially “gamified” and simplified a movieola (35mm film editing hardware) to be the player’s interface with the game. The process of scrubbing through footage, marking favorite clips, cropping in on items of interest, “match cutting” (sort of), made for an incredibly immersive experience. Honorable mention goes to the music raising and lowering or shifting as I sped through or slowed down on footage - it created such a unique gaming experience.
What are some examples for y’all?
Speaking of time mechanics, Touhou Luna Nights is a pretty short metroidvania where you play as a character that can stop time and they really nailed the time stop mechanic. You can use it to avoid the very difficult to dodge attacks from the bosses and they're an essential strategy to counter some of the attacks, what's more they allow you to launch a lot of daggers which will only hit when you restart time and that is very satisfying to do. The plateforming also benefited from it, with things such as moving platforms to freeze or climbing on top of the daggers you launch yourself after stopping time.