Comment by camtarn

Overwatch was prototyped by making levels out of plain boxes, using character models ripped from a previous game, then iterating until the game mechanics were fun. Of course, it then received many layers of polish before it was launched, but nonetheless the devs prioritised getting the basics right first.

The dev team had just come off developing Titan, a cancelled MMO where they had trouble making the core game loop engaging after seven years of development, so they had a lot of motivation to start small and make something good first, then polish later.