Fast fall
Also said as Fall gravity, Asymmetric gravity
Stronger gravity on the way down than on the way up. A real thrown ball has an even arc; a good video game jump usually does not.
An even arc looks correct and feels like floating. A quicker fall gives the same jump weight and shortens the wait to act again.
Say it
“Jump feels floaty. Keep the height at 150 px, take 0.36 s to reach it, and multiply gravity by 1.7 on the way down.”
Where you’ve seen it
Super Mario Bros. already pulled Mario down harder after the top of his jump than on the way up, and most tight platformers since have done the same.
Not to be confused with floaty
Floaty is the complaint and fast fall is usually the fix. Floaty comes from too long in the air, especially on the way down.