Note: read “first” as “first popular/important”, not just for this thread but for most conversations across media like this.
Spelunky was the first “Roguelite” that brought permadeath with meta progression to another genre, starting the modern wave of Roguelites.
Pokemon kicked off “monster collection” as a mechanic
To my knowledge, Halo was the first major game to do regenerating health
I definitely vote for the Piantor by Beekeeb