The game was created almost solely by Toby Fox, along with a few art assets provided by Temmie Chang. Hidden behind an apparently low-effort artstyle is a beautiful and intricate storyline, lovable and memorable characters, award winning music, and an interesting and unique combat system. This expectation subverting hit took almost anyone who played it by complete surprise.
No list of games made by one person would dare miss Undertale. Undertale has a deep and moving storyline.