I think Warcraft III, it built a certain mixture of gameplay and lore that one way of another shaped all the games I regrettably sunk way too many hours into:
- World of Warcraft
- League of Legends
- Dota
I would say Shufflepack which made me into a kid that wanted to played videogames all the time, but I feel that has not "influenced" me much, and any other title would have had the same effect.
Outer Wilds has a very elegant diagetic tutorial in the form of a museum and, well, a training ground, whole game is really a multi layered tutorial with scaling level of complexity.