I have some thoughts based on the many years I've been playing games, and I think I can boil them down to two points:
- There are entire game genres which I find unplayable, with a few rare exceptions, but I don't think adding options to make them easier or adding cheats is necessarily the answer, and unfortunately probably the answer is completely different game design (e.g. more Tyrian, less every other bullet hell game).
- What I find most enjoyable is when the baseline difficulty is playable but then you can turn on a challenge mode, or raise the difficulty in a way that makes it a greater challenge, or when the game is flexible enough that you can play a self-imposed challenge. I use the examples for each of these of GITCL, Max Payne 2, and (the original) Deus Ex.
First I want to note that I have never extensively played any Souls or Soulslike games, because I bounced off of the first Dark Souls or Demon Souls or whatever hard and never tried another Fromsoft game (and don't particularly want to). So I have nothing to say about Soulslike games, and my comments are all going to be about other things. (No, I don't remember which one it was.)
The problem I have is this: there are entire genres of games that I have found unplayable or nearly so, with few exceptions. I so wanted to play through Enter the Gungeon, but no matter how many times I played, I did not get any better at avoiding enemy shots when there were a lot on the screen, and I did not get any better at timing my dodges - I consistently mistimed them and got hit. I could sometimes beat one of the possible first bosses, if I got a weapon I could use against them effectively, but the others wiped the floor with me, and every time I did get to the second level, the regular enemies killed me almost immediately. I've found pretty much every bullet hell game I've tried impenetrable for the same reasons - there's too much stuff to process at once, and I repeatedly mistime my attempts to avoid the projectiles. The only one I've actually found playable, and felt like I could get better at, and done well in, is Tyrian. I'm similarly terrible at most platformers and sidescrollers and never seem to get better at them no matter how much I try to practice (Spelunky, for instance), though there are a few that I've done well at and enjoyed (Stealth Inc 2, for instance), and by the time I finished, felt a sense of mastery of. I don't know what the difference is between the ones I can't seem to get good at, and the ones that I can master, but there's clearly a difference there somewhere. I also find roguelikes the opposite of fun, but that's a whole different thing (it has the same feeling as if you build something cool out of Legos, and then someone throws it in the trash). I have also not been good at, or even halfway competent at, a fighting game since Street Fighter II (not that I ever had the opportunity to play it enough to get really good at it). I can't seem to do the quarter circle whatever things well enough to satisfy the modern games, and the timing continues to be an obstacle.
Since Celeste was mentioned, I want to note that it's one of those games that I couldn't get very far in because of the platforming, until I said fuck it and turned on all the accessibility options to basically just let myself fly through the levels, skipping the platforming, so I could see the plot. Because, to be clear, I was only playing because I wanted to see the plot. I don't enjoy platforming - I find it incredibly frustrating (with the aforementioned rare exception of Stealth Inc 2). If I'm trying to play a platformer or a fighting game or anything remotely bullet-hellish, it's probably because I want to see the plot. So I can see how options like Celeste has could potentially be a good thing. I should note, though, that even with Celeste's accessibility / god mode options, I never finished the game. I actually lost interest partway through. Going from impossible (for me) difficulty to no difficulty was not the solution, apparently. But Celeste did not seem to have whatever it would take for me to enjoy the platforming, no matter which options I turned on (I tried them individually before I started combining them). But I couldn't tell you what that would be. I've never figured out what it was about Stealth Inc 2 that made it playable, masterable, and enjoyable for me, in contrast to virtually every other platformer I've ever played (I like Terraria too, but I wouldn't call it a platformer). I have no idea how the plot goes in Gungeon because it has no way to make it easier, and the difficulty was such that I only ever made it to the second level less than a third of the time, and that was as far as I ever got. There are many other such games that I had to turn away from even though I was interested in the plot. (It's funny, watching someone else play games on YouTube isn't really fun either)
And yet, curiously, I only seem to have difficulty with timing in those kinds of games. In first or third person shooters, I don't have any difficulty with timing (now, I'm terrible at sniping in basically all FPSes, with the exception of the DMR and battle rifle in Halos 1-4, ODST, and Reach, where I can land repeated headshots at range on a moving opponent, but I continue to be terrible with the actual sniper rifle). In the original Star Wars Battlefront, I mastered the timing to such a degree that I regularly fought rocket-launcher-armed enemy players in the multiplayer at point-blank or near-point-blank range and dodged all their shots by simply not being where they were aiming when their weapons fired. I used the handheld mortar weapon and won those duels virtually every time, despite them dropping mines that I also had to avoid. It honestly felt more like being a Jedi than playing one in (the original) SW:BF2 did, even though everyone in SW:BF1 was just a regular trooper. But of course that was also a long time ago, and virtually everyone (else) used the rocket launcher, which made it easier. I used it also if I couldn't use the mortar; only two of the four factions had it, iirc. I could name other examples, but probably the difference isn't the 3d vs 2d, but that it's easier to process everything in the 3d games because they're less overwhelming. I only had to track usually one, at most two enemies at a time in SW:BF1 because the bots and most players weren't at a skill level where they were even a challenge - I would just instakill them and move on. Unlike in the typical bullet hell game, where you tend to have numerous enemies you have to track as well as numerous projectiles, and where your ship explodes if they so much as scratch the paint (of course, those rockets in SW:BF1 would also instakill if they hit, but tracking one person's reload time is a lot easier than tracking a dozen enemies and 90 projectiles or whatever).
Rather than the usual method of "this is the normal mode but you can make it easier if it's too hard," or worse when there's no way to make it playable for you, what I have found that I have enjoyed most are games where there is a baseline difficulty level, and then you have the option to make it harder. For example, Christine Love's (@love) Get In the Car, Loser has the devil's clock which you can turn on to add additional challenge to the game. It basically gives the enemies additional abilities which kick in after a bit during the battles. Max Payne 2 has the normal difficulty level, and if you beat that, you unlock the next difficulty, and so on, and if you get so good at the game that you successfully beat the hardest difficulty level, you get a special ending - the ending of the game actually changes. I beat it on that difficulty back in the day. Deus Ex (the original), has multiple difficulty options, but also has such a range of weapons and items and different ways to play, that you can create your own challenges, like a self-imposed no-gunpowder-weapons challenge, or a non-lethal challenge (I made an exception for the bosses). For me, at least, the self-imposed challenges were what made it really fun to replay.