Well, let's mostly consider RPG. If not, well you might include many factors that are not is some other games that you might like.
You can play strategy games, plateformers, tower defense or other games that have next to zero story and are still fun because of the system, the art, the gameplay or the whole package.
RPG, on the other hand, have you spend quite some time (even short RPG are long compared to some other games) in it, being immersed in a gameworld, interact with people and maybe dwelve into politics.
It cannot escape having some kind of writting. That writting can be the plot, the side quests, the dialogs, the setting, the visual writting, the consistency, etc...
If that writting sucks, and sucks hard, you can't help to wonder why the hell you are bothering with helping those people, accomplishing those tasks, walking in those street.
Even if the gameplay is good, too bad writting will prevent you to fully enjoy it. On the other hand, if the gameplay is minimal but the story beyond awesome, you might not consider the game as a masterpiece, but you will certainly want to play it through the end. So, i guess i am mostly a storyfag.
Next, i would say C & C. Even if you only play the game once, an RPG, or even a game that have good C & C will emphasis a lot more, not only on the player agency, but also on one of the very aspect that set the game apart from a book/movie/song/etc... As an interactive medium, games are supposed to put you, as a gamer, at the forefront of the experience, by not only make you participate, but by making your input a central aspect in how the story is unfold. I might be pretty naïve, but my conception of a modern video game in general, and especially RPG is to enhance the amount, the depth, and the free flow of C & C (never lampshade those, just make them). I don't think that C & C should be an exclusive RPG/Obsidian/RPG Codex territoy, but something any develloper should thrive for. Sadly, we are still trapped into the territory of primitive corridor-y FPS or big bland landscapte gameworld.. C & C shouldn't be hardcore or old-school, but the future. Otherwise, you might just watch a good movie/TV Show. Also, as long as those games lack C & C and emphasis on hand-holding, it is detrimental to the immersion, as the game refusing to aknowledge your previous action, you feel like you are outside of the narrative.
About exploration, i cannot choose it as i doubt i share the same definition as others. For most people i read, exploration seems the ability to copy-past a bigger and bigger number of generic landscape. The gameworld is 1000 miles/kilometer big, so it must have a lot of exploration. If it is what exploration means, i must say i hate exploration. I don't see the point of having tons of miles/kilometers to walk/drive/teleport into if there is nothing valuable in it. On the other hand, i consider i spent a lot of time exploring gameworld, when those were content-heavy, and quite smaller. The time i spent in Vizima, New Reno or Vault City IS exploration, IMO. The maps might not be that big, but there is ton of contents in it. You can spend dozen of hours walking the streets, talking to npc, learning things about them from other sources, be acquainted with the politics, the power struggles, the daily life of the location and its surrounding, doing quests, making choices between various entities, slowly taking a pro-active role in this envirronnement. You don't dwelve into an empty landscape full of generic critters, but into the customs, rules, issues and daily life of a living world, and the work of some talented creators. When the game succeed in putting enough depth into that world, without harrassing you with tons of useless fillers, then i can say that there is good exploration. But sadly, games that offer that are pretty rare IMO, so if i would get to choose only those who provide that, i wouldn't play much. There is also another aspect that i can consider exploration, is discovering non-obvious things, that are easy to miss by most players and be rewarded for it. You had an active role in scratching everything to get to the hidden gem everyone else missed. Sadly, that aspect is also rarelly present. I recently played WL1 and started WL2 and i was pleasantly surprised by the amount of hidden content. But if you really want to get those things, you need to play with a completionist mindset. Unfortunately, if you play a game full of filler, a completionist mindset would make those fillers even more destructive of the game, as you would "explore" all the fillers and spend too much time it. So, in the end, looking for exploration might be a doomed attempt in many games.
About combat, i would say that there are few games in which i enjoy the combat, and that i am not crazy on game that are overloaded by combat. Rather than unecessary generic battle at every corner, i would prefer less combat with interesting design, or more way to avoid battle. One of the best aspect of my favourite series, (Fallout) is that you can avoid most of the combat and not miss out much of the content. (at least for Fo1-Fo2-FoNV). But even in games i enjoy combats, they need to put good story/setting with it, otherwise, there is just so much combat you can endure before getting bored. Also, if the combat is playing a significant part of the game, i prefer it not being messy and being able to see each part of it, so i prefer isometric TB or isometric RT, so you actually see what is happening on the battlefield, not just through the eyes of just one of the guys that may be running away because he needs healing. Also, i prefer the combat to mean something. You don't just fight because you have a weapon and a target in front of you, but because you want to survive, because you want to release the country of Arulco, because you want to make become the head of the mob in that 30s city, because you want the Aztech out of the gold mine so your brittish villagers can mine there and get to the Castle Age before the Japanese, or because those yakuza are guarding the macguffin your johnson paid you to get, not just because there are critters on your way during a meaningless travel between metro station 23 and sewer 14, a kind a location you already visited 20 times with nothing special in them. Otherwise, fight should be fun, short and involve some other factors. Anyway, combat is a mean, not an end.
Also, art, graphic & design can add a lot into the game. But it mostly have relevant the first few minutes/hours you get into a location. Afterward, those streets/roads/doors/containers/etc are just tools supposed to be part of the gameplay. As long as they retain their efficiency, they can be from any style/technology/decade. As for the gameplay itself, most of those are category. You often choose a gameplay because of what it allows to do/see, what design it does serve, and how confortable you are with it. If the gameplay get in the way, it might cause some pain, but if the content is worth it, you are most likely to continue. On the other hand, if the gameplay is good but the content poor or generic, you might forget you even started the game and get into something else. Currently, there is an overload of new stuff, and the old stuff is still available. You aren't likely to keep going on something totally uninteresting despite its totally awesome gameplay... Unless that gameplay is one of a kind. Not saying their content is bad, but i would understand someone who keep playing Myth, Commandos or Jagged Alliance 2 despite not loving the setting, the story, the tone, the design and the graphics. There is just no other games to play with that gameplay. As long as there is another game that have the same gameplay but a setting you enjoy more, why bother with the bland clone ?
About the depth of the system, how perception matter compared with stamina, how much the engagement system should be toned down, is making a monk worthy etc... Those aren't things i consider too much on first playthrough, unless my first approach is totally doomed or i want to reach a specific thing. I mostly use them as tools for RP, not judging the depth of those stats efficiency. If i replay it more, i will dwelve more into it as it will mean the possibility of new content, other ways to experience the same game. But the first time, i mostly consider them as general options/tools/flavor, unless i get it straight away. And even after dwelving more into it, i never mix/max, never try to reach the best combination, or make balance study of the classes. On the other hand, i don't get some critics about some game not possible to finish if you made the wrong build. It might be true with some games, but for the most RPG i played, some of which mentioned as requiring to restart the whole game many times for proper build (like Fo1 or WL2), can be finished with a garbage character, as long as you are patient, use your wits, and be ready to overcome challenges or avoid them entirelly by playing around the location geography. As long as it is technically possible to win, no matter if it increase the difficulty, every character is viable. (not "If it is not easy, the character is not viable")
