I was trying to think of which games created certain mechanics that became popular and copied by future games in the industry.
The most famous one that comes to my mind is Assassin’s Creed, with the tower climbing for map information.
How about the flowing hair on Lara Croft in Tomb Raider 2 and later?
From my understanding, they wanted to have that working for TR1 but missed the deadline, so Lara got a static hair bun in TR1.