One hour is more than enough to judge a game

[Darashiva]

I think it depends on what the game's main draw is. If its a platformer then it's usually easy to judge the game quite fast as in them the basic gameplay is probably the most important aspect, and an hour is more than enough to see if the gameplay work. However, if the game is strongly focused on storytelling, 1 hour usually isn't enough to judge whether a game's story is good or not.