Basically, I want to save Asriel, and the inability to do so cuts rather nastily against the game's themes in a way that I'm pretty sure is intentional.
One of Undertale's big themes is that everyone can be pulled from the fire- there's no one who's actions are so heinous that they cannot be helped, even if you have to play merry hell with the timeline in order to do so (hi, Asgore). A pure pacifist run is pretty difficult, and to ensure that you're not going to kill even one monster is not the easy route out, but it feels like it pulls it's punches at the death with Asriel- he simply cannot be redeemed for longer than a few minutes, and the player is given no option other than to abandon him to his fate in the flower patch. Asriel is, lest we forget, an innocent, who paid for his friendship and his refusal to harm others with painful death, soullessness, a never ending cycle of repeating mistakes and the nihilism which comes from all of that. To not even have the option to do anything other than give him a hug and leave him to suffer through the same hellish existence all over again... Not for me. No one has to die, but no one should have to live like Flowey either.
Flowey is, of course, the game's most nihilistic character, and to leave Asriel to turn back into him with absolutely no opportunity or even chance to save him from it... Well, that's heartbreaking. I fully understand that's what Toby Fox was going for, and all credit to him for inspiring these kinds of emotions for a character that we barely meet, but to go through all the work of SAVING Asriel in the last battle only for him to be doomed as soon as it's done... It doesn't quite sit right with me. Asriel makes a great self-sacrifice at the end of the game, and I'd like the player to be given the option to make one instead.
Of course, saving Asriel shouldn't be easy. Generally in this game, the heavier the character's sins the more difficult it is to show mercy, and Asriel's actions almost bring about the end of the world several times. There should be some stringent conditions to ensure that only the most dedicated players will even want to try, of course, and some heavy consequences for failure. Pretty much every idea I've read on the subject of saving Asriel requires the player to make countless runs through the game, and to tear up the happiness in the true ending for a chance to save one more person. The moral implications of jeopardising a happy ending for the chance of a slightly happier one feels like a theme that would be well within Undertale's wheelhouse, and the idea of judging the player for wanting the happiest ending possible regardless of the consequences would be an interesting take that the main pacifist ending didn't touch on all that much. Whether the method's some Sans-tier extra fights, or having to replay the game at a higher difficulty, or even sacrificing your own morality- how evil would it be if the only way to save Asriel was to do a genocide run?- it would have to mean something tangible for the player.
I think that any permanent saving of Asriel would have to impact future playthoughs, too. In much the same way that the player's decision to be as much as a bastard as possible leaves marks on the game, so should any decision that amounts to self-sacrifice. Honestly, I wouldn't mind too much if the game actually locked you out from playing it again having saved Asriel, particularly if the method of doing so is the long-speculated "Frisk gives Asriel his SOUL" way, but I'm pretty sure that would be breaking EU regulations if nothing else. There should be something, though, be it locking you into hard mode in all future playthroughs, or even just changing the endings like the genocide run does. Something as big and difficult as permanently redeeming Flowey should linger, be it for good or bad reasons.
BTW, I've seen Toby's tweet about future updates only being bug fixes, and I don't fully buy it. It would be so typical of this game for a bug fix patch to contain important new content hidden away, and adding content is explicitly mentioned in-game. It's not like I'm at all unsatisfied with the game as it stands, but I'm not at all convinced we've seen the last of it.
