What is Doki Doki Literature Club, the 'dark' game linked to a teenager's death?

Police have issued a warning to parents about a computer game that poses “a risk to children and young people, especially those that are emotionally vulnerable”.

Boy, 15, found dead - and now his dad is warning parents about 'dark' online game that 'dragged him in' - Mirror Online

What is Doki Doki Literature Club, the 'dark' game linked to a teenager's death?

Father issues warning over 'dark' video game - PressReader

Is it bad that I got depressed of a game called Doki Doki Literature Club? - Quora

What did you think of Doki Doki Literature Club? - Quora

Making a Monika mu tierlist. I don't expect many opponents but please give me some : r/DeathBattleMatchups

Inside twisted Doki Doki Literature Club game which parents say caused 'suicide' of their children – and it's horrifyingly easy to get hold of

History Repeating Itself: Doki Doki Literature Club Blamed For A Teen's Suicide – Yuki The Snowman

Doki Doki Linked To 15 Year Old Teen Suicide, According To The News