Filming only cost $500,000, while the digital effects cost an additional $10 million.
The film was completely financed by Greg Strause and Colin Strause without the assistance of any major studio.
Most of the large alien spaceships were designed from the different appearances of various low-altitude clouds ranging from Stratocumulus to Cumulus.
Sony Pictures launched legal action against Greg Strause and Colin Strause and the owners of Hydraulx Films on the basis that the latter had been hired to provide the special effects for the similar Invasão do Mundo: Batalha de Los Angeles (2011). Sony claimed that Hydraulx had not informed it that the company was working on a competing project. The case was later dropped.
The Brothers Strause claimed that this was just the first in a series. The film's lackluster box-office performance suggested otherwise, but a direct-to-streaming sequel (Beyond Skyline) did eventually appear in 2017, as well as a further sequel (Skylines) in 2020.