Angel Fell

A girl falls into the underground. Raised for nearly two years by the motherly caretaker Toriel, she decides it was time to leave. However, the ruins were so much kinder than the world outside. While all she met were froggits and Whimsims, she never expected that the residents beyond the massive doors would be out for her blood. Alone, she makes her way through the land of monsters to set herself and them free.
(Will not follow the game exactly. Darker but not Underfell.)