Square Enix explains the various connections between NieR Replicant and Automata, including the various cameo appearances ...

And when 9S hacks into him, he sees Emil's memories, showing Kain, Yonah, Grimoire Weis, and Nier in full. This is one of the ways the anime ties into NieR Replicant much closer than the game.

Automata saved the Japanese games industry. According to Yoshida, the game was so well-received and so unequivocally Japanese ...