Little heads up that another Undertale fangame, that features the Integrity Soul, and is meant to be prequel to Undertale Yellow was recently released.

https://gamejolt.com/p/aaaaand-it-s-out-have-fun-and-do-leave-some-feedback-at-this-goo-cmhnct8b

demo for undertale promise (the yellow prequel with integrity) scheduled for august 15th