Lindsey Morgan (Rose) and Yayan Ruhian (Huana) are the only returning cast members from the previous installment, Beyond Skyline (2017). However, the character Trent also returns as a Hybrid along with flashback scenes from the previous movie showing him as a human (played by Johnny Weston).
At 1:21 The General quotes Vishnu in the Bhagavad Gita, "Now I am become Death, The Destroyer of Worlds" This was originally said by J. Robert Oppenheimer about the atomic bombs dropped on Japan.
The post-production for this film was done during the shutdown caused by the 2020 COVID pandemic.
At 1:98.28 Dr. Mail quotes Dorothy in "The Wizard of Oz" when she says "We're not in Kansas anymore".
Rhona Mitra and Jonathan Howard both were on the show The Last Ship, though their seasons did not overlap.