3D Construction Kit was a utility enabling end-users to develop games developed by Incentive Software/Domark.
Using the same Freescape system they had employed in these games :
Video
A video tutorial was distributed in the package, on a gold VHS tape.
The video tutorial demonstrated construction in the Freescape environment (Amiga and ZX Spectrum).
The Amiga version specialised on creating a tunnel which when shot, would make the roof vanish and the left wall move to join the right wall.
They also built a house and another area and bridged the gap between areas.
A border was added and a basic game control was added.
The Spectrum version dealt with the tunnel and shooting.