Futuristic

The  style is a style that was used in PUNT and PUNT: Rebirth. In both cases, the style was removed in favour of the retrofuturistic style, with the stated reasons being that the developers would prefer if the game had a more notable identity of it's own and that they had always wanted to play into a retrofuturistic theme.

PUNT
The style is characterized for having a sterilized facility look, with the test chambers being made out of very clean panels and square elements (the futuristic style made heavy use of squares). The panels are for the most part, white, with certain sections of the chamber being colored or having panel 'blobs' of color. The main light sources in the test chambers are the observation rooms that emit a green-like light, with certain sections of a chamber being aided by big square light panels that can emit either a warm or cold light.

PUNT: Rebirth
The futuristic style in PUNT: Rebirth has for the most part, not changed from Reepblue's PUNT, even going as far as reusing assets from the 2012 PUNT version. In this iteration, the coloring has become a lot less colorful, featuring more yellows and beiges. When this variation was being developed, the style seemed to be undergoing a shift, with the some of the elements being noticeably less square (The cubes being a specially notable example.)

Trivia

 * Despite being scrapped from PUNT, Reepblue actually tried to iterate further upon the style in Vectronic.
 * The style is extremely similar to the test chamber style seen in Portal 2.