At 51:09, Erlang Shen (Shawn Yue) tells Sun Wukong (Eddie Peng) he is mad for trying to save the villagers. Shawn Yue was the lead actor in Mad World (2016) where he played a madman just discharged from a mental hospital.
At 1:34:27, when Wukong steps out of the smoke, the song playing in the background is identical to the song that plays in Stephen Chow's "A Chinese Odyssey Part 2" when The Monkey King interrupts the wedding between Bull King and Zixia at 1:17:04.