When you say you never died against Asriel I feel really incompetent.
Anyway, I didn't actually think you could die against Flowey in the neutral route. I mean, if you actually can, then I guess that's nice, but I felt like I played it really poorly and wasn't punished nearly enough for it, so about 20% into the fight I just concluded that I couldn't die because my life total didn't move in a way that made sense to me. Which took me really out of the experience.
Here's the weird thing between us, then: I died several times to Flowey in the neutral ending, but then somehow kept managing to survive Asriel's attacks by some sliver of health. In a weird sort of mirror to you, I had been under the assumption that it wasn't possible to actually die to that final boss. I wasn't taken out of the experience for it, though, although considering just what the "experience" of Undertale is, I wonder just where that line is supposed to be.
Murdering everyone seemed pretty unforgivable tbqh.
Here's the thing, though: you are always given an out. Every major character sees the good in you, thinks you can change your ways. Papyrus especially, even as you grind him into dust he talks about being SURE that there is a good person inside of you. Sans's entire monologue during his fight basically boils down to "you can be better than this, if you just stop here". It's part of why Undertale works as a psychological analysis.
Supposed to give me what feelings? I don't play games to be bored or dismayed. If you want to convey an emotion through poor design, then fine, I guess you can do it. But I'm not going to think any better of the experience because of it. Just give me a written note instead of wasting my time. I'm not opposed to games as art, but "you feel bad because the game is bad" isn't how I see its future.
Undertale isn't "the future of games" any more than Eva or Madoka were "the future of anime". It may have gotten wide-spread attention, and may in fact be influential (it is FAR too early to say), but ultimately its appeal is niche, and a lot of people may end up hating what it did. In my eyes it's a subversion of expectations from the JRPG formula, where the normal expectation is to be rewarded for grinding by facing greater challenges and get more loot, and the subversion here is that you are challenged less as you go along and have less need for the loot you are rewarded with.
It also seems to me to be a logical extension of giving all the enemies a unique character instead of just filing them under "enemy" -- when all these enemies are supposed to be individuals, you're not supposed to feel enjoyment by killing them over and over. As someone who looks for games that do more than deliver a single emotional state of "fun" or "awe", I love that Undertale tried (and for me succeeded) to deliver guilt. I think you can make the argument that the delivery of said guilt can be a little ham-fisted at times, but unlike so many other games that try the same, Undertale never forced you to do the things you did.
Unlike in, say, Dark Souls, where you're forced to murder a puppy. Or in Brothers: a Tale of Two Sons, which forces you to do another thing (though it's still a bloody powerful moment). Not that I don't think those games are well-designed, but I feel it's kind of cheap to put you in a situation you CANNOT back out of and then emotionally punish you for it.
I probably could have killed Sans if I wanted to, although not in as few tries [le snip]. I don't really mind that he was difficult [le snip], but I do mind the disproportionate difficulty curve between him and everything else but Undyne. It just doesn't make sense to me. Like, why?
Unless Toby Fox just ran out of time or energy to make more boss fights, I imagine it has to do with the content deprivation I mentioned, to make the grinding bit even less rewarding. On a personal note, I don't entirely think it worked as such, but that's my guess.
As an aside, I forgot to mention, but the "nobody appeared" messages became really annoying after a while. I got it the first time, thanks.
You mention that but not Alphys's bit parodying tumblr/twitter/facebook? I feel that's the bit most people get annoyed at. But I agree with you. Once you hit that magical number I swear the encounter rate goes up just so that you can be stopped every five feet, like in a Zubat cave. After the first time I carefully timed where I got that last encounter to just before the boss room.