From GameWatcher: “Beyond a Steel Sky is essentially a standalone release, according to Revolution Software CEO, Charles Cecil. Since its predecessor, Beneath a Steel Sky, released way back when in 1994, the developer is hesitant to call the new release a sequel.
Cecil cited immense differences in tech as the main reason they’re not banking more heavily on Beneath a Steel Sky’s pedigree, and it’s a rather sensible argument, all things considered.”
Source: N4G PC Beyond a Steel Sky shouldn't be considered a direct sequel