For many great games, often the most difficult thing to quantify is the 'feeling' of them. By this I mean that combination of crunchy, underfoot SFX, the character animation and the way they conduct themselves through the game environment.

Think how Link moves through Hyrule in Ocarina of Time, how Aloy walks down mountain paths in Horizon, how the cars turn corners in Forza.

Forget objectives and story and graphics and all the other nonsense; just the act of moving through the environment in whatever form that may take and just existing in that game world is what elevates the game and demands repeat playthroughs.