Premium
Also said as Pay once, Buy to play, B2P
The player pays once, up front, and owns the whole game. It is the oldest model there is.
The deal is clear and your design has nothing to fight: every decision can serve the player, since you were paid before they started. You also get just one sale per person, so you have to find enough people.
Say it
“We are premium at $20 with no store in the game. Our budget has to pay back on about 50,000 copies after Steam's cut and discounts, so let's check that against what similar games really sold.”
Where you’ve seen it
Hollow Knight sold for $15 with no paid extras of any kind, and its later content updates were free.
Not to be confused with free-to-play
A premium game earns at the door. A free-to-play game earns inside the game, so it needs people to stay and spend.