I 💯 went through this disappointment. I used to also love looking at a game's concept art because they always looked so much cooler and atmospheric than the game. I remember the inflection point clearly. I was playing Mass Effect 3 and walking around the citadel wards/docks, with it's beautifully detailed textures, evocative colours, and painterly lightshafts, feeling absolutely enthralled, and thinking "Holy shit, they've finally done it, the gameplay looks better than the box/concept art."