Earlier quoted context omitted.
Before Minecraft became a game, what was it?
Exactly what it claimed to be: An alpha/beta test for a game.
If you weren’t told it was an alpha game you’d have no way of knowing. It sold a million copies while in alpha/beta, more than most other games ever made. The distinction between “alpha/beta test of game” and “game” is a distinction without a difference, especially for all the people buying it.