I'd argue that graphics in particular help play a role with AO titles, because while it's possible to sell a purely or mostly text-based adult game, it's much easier to sell one with shiny, top-of-the-line graphics because that has a much wider audience. This is why Studio Fow's Subverse is worth paying attention to once it goes on sale, because that's a 3D porn movie studio, specialized in graphics, making the jump to porn games. If that does well, it's a good litmus test for AO games to follow.
Good point on graphics and AO, I have to agree. If you can differentiate yourself from the competition it's always worth doing - to a point, anyway. But seeing how popular certain AVNs are, I would still argue that graphics are only A pillar on which the game has to stand. Having "good writing," an interesting story and interesting characters will make
imo for a more memorable experience no matter the graphics. Though I will say that I'm most likely biased by my own experiences and preferences.
So, fun fact from a long-term perspective: people often learn aspects of game design by internalizing things from games they've played, as much as by actually actively trying to learn things. This is why, over the last twenty years or so, you've seen a top-down trend starting with AAA games and ending with indies where game design has shifted, pretty dramatically. We're now seeing indie games, like Eco and Valheim, that use some core time based mechanics that are, frankly, the opposite of fun and originate from free to play (but not free to enjoy) mobile games and have managed to permeate the entire industry. In many ways, the industry at large is beginning to forget what makes a game "fun" in favor of mechanics that rely on addiction.
I understand your point on the design shift, but not your example though. I haven't played ECO, though I have played a bit of Valheim, but I don't get the "core time based mechanics." Do you mean the food/health/stamina bar system? I would see it more as a system, though you did mention exactly that. However, none of it is behind a paywall nor is it imo incredibly grindy to be "opposite of fun". I do think that hunger mechanic can go and die a painful death.
I'm probably a bit too casual to understand mechanical development as you put it, nevertheless I will say that investing into "addiction" instead of fun is a good move from a business stand point. Though for a game like Valheim it matters neither here nor there, as there are no "recurring payments" to be profited from. An ego boost for the devs, maybe, for having 5+ million players?
But you need to have some challenge in a game to offer the gamers™ some sense of pride and accomplishment for their overcoming of said challenges. Games require some sort of a reward system - obviously it needs to be balanced somehow - to be fun. The fun might be the "sense of accomplishment" from overcoming a difficult (but hopefully fair) level, chainsawing through a demons head, or seeing the next "page" in a gripping story. Sure some art project might be just watching paint dry and that can be fun in a certain ironic sense, but I can't imagine it would last for more than a few hours. Though I will say that certain games benefit from having no real challenge - I for one enjoy playing city builders occasionally without limits, just for the sake of designing a city.
I'd say it depends on the genre. Take action/adventure games, which vary from Breath of the Wild to Tomb Raider. While both of them involve combat and exploration, the means of accomplishing those are dramatically different. Portal is technically a first person shooter, but it was made as a puzzle game. Pokémon and the older Final Fantasy titles are both turn-based combat-focused jRPGs. The classic Mario and Sonic games are both straightforward platformers, but a few core mechanical choices make them feel like entirely different games.
The point being that there's a difference between placing a game in a genre, and mimicking a specific subset or game from the genre.
That is the problem with less defined genres. "Action/Adventure" means very little really, because your examples could arguably also be categorized into survival games or platformers. I think the correct way would be to consider these terms as both genres and elements.
An "FPS genre" game is usually a game where you are some lad/lass with a gun shooting "enemies." But on that merit without further defining it, GTA V is also an FPS and so is RDR2 - and I don't think many would categorize them as that - not straight anyway. BF and CoD could be part of a "military-game" genre with
heavy FPS-elements, GTA V and RDR2 an "open world game" with a story focus and FPS-elements. Then we can further muddy the waters by defining FPS, first person
shooter. In Portal you do have a portal
gun, but it's not a "straight" shooter. You have enemies in it, but you kill them using the environment. It is an FP game, but that doesn't sound nearly as sexy as "FPS." In reality though, the FPS-term really doesn't include the shooter part as any game played from a 1st person perspective can be considering an FPS in general.
There's probably a language barrier here, a certain lack of understanding beneath the surface, and me being a mindless consooomer. I also have a bad tendency to ramble, so hopefully at least part of the above is somewhat coherent. Nevertheless, it is good to argue (positively) about these things as it expands ones own perspective.
IF it does and you get the game to load, press "o" in game to open the load game window, and use the settings there to TURN OFF the auto save option, that should help
I'll keep that in mind for next time