As someone who lived through that era, let me tell you, the gameplay graphics were never a disappointment. In your mind they looked as good as graphics today. The only thing I can remember being disappointed about was the Nintendo Powerglove. Man, what a collosal, non-working, over hyped advertising lies, piece of shit that thing was!
I remember renting Phalanx just because of the box. like "why's this old man playing the banjo?" then you look at the back and it's a friggin space shooter. I had to rent it.
My games were all pirated. Covers had a handwritten list of all games on the cassette (and later CD). The first legit game I've ever seen was Mortal Kombat Trilogy and I remember being taken aback by the waste of using a full CD for a single game (iirc the game used just 30 MB of space on that CD).
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."
I can't research it at the moment, but I want to say that was a common thing in the pre-NES days, and I think Nintendo required actual gameplay graphics to be shown on the box because of that.
Could be off on the specifics, but I do vaguely recall those kinds of non-representative box art having some controversy.
I had Bad Street Brawler for the NES and it's so bad, it's funny. Even back in the day.... fighting midgets, dogs, and circus strongmen, trying to get to the dumpster at the end of the level, and with 2-player coop to boot
Honestly graphics aren't really that important compared to the gameplay. Games such as those in the UFO 50 collection are a really good example of that. Also if you actually want a quality god vs satan game with old school graphics then I highly recommend Grimstone.