Toby Fox updated his Undertale tumblr account (that he never uses) recently. Here's what he had to say.
"Retrospective on UNDERTALE’s Popularity
Though it was released almost a year ago, I have the same opinion of it.
It’s about an 8/10, niche RPG game.
If you like the characters and the humor, you’ll probably like it, and forgive it for its flaws.
If you don’t, you’ll probably hate it.
Surprisingly, there are many people who like this type of game. Though I did work hard, there’s definitely a lot of luck involved in having a game become this popular. So, it wouldn’t surprise me if I never made a game as successful again. That’s fine with me though.
Not only did I not expect this level of popularity, but initially, I was afraid of it. I didn’t want UNDERTALE to become tiring for people, or become spoiled before anyone even got a chance to play it. Early on (this was probably excessive) I even tried to contact certain Let’s Players to tell them not to make any content about it.
But, the game became very popular. Unavoidable, even. At the height of its popularity, “not liking the game” felt like a cardinal sin to many fans online. In reaction to these circumstances, others began actively hate the game, creating an endless whirlwind of discourse…
Like a thunderclap to a small dog, all of this attention stressed me out. And every time it seemed to die down, something revived it, such as the GameFAQs contest, the award shows, bizarre theory videos, and so on. At times, I wished I had a way to quell the attention. I felt a strange powerlessness. (And guilt, for feeling stressed when the success of the game SHOULD be something I’m nothing but ecstatic about.)
At the same time, countless wonderful things were happening. People told me the game helped them through a difficult part of their life. Others told me that the game had made them laugh, or cry, or say “I want to bePost too long. Click here to view the full text.