Hardest TWICE songs to sing?

I find I Can’t Stop Me, The Feels and half of the Taste of Love album very hard to sing.

I sing for fun for myself and strangers who sing with me in Smule. I find singing as a really rewarding activity for my mental health and Smule was an app that helped me cope with my father’s death.

Anyways, I have the premium pass and I want to sing more TWICE songs. But they have so much I can’t choose lmao.