I think that’s fine. While a little more can’t hurt, most people won’t spend more than a few minutes to test your game anyway – during the rating phase at least (there are exceptions obviously, but given that many people here will test around 20-100 games, there’s just no time to play each one for an hour). So if they’re even able to play it till the end and see the credits roll (given your game has credits :D), that’s probably a good thing.