User summary:
Adeptus Evangelion - Borderline resulted from a schism in the development team after the v2.5 development of the "main" game. It was published prior to v3, and some of the early development work on Borderline eventually was folded back into v3. Borderline went through four major revisions (2011, 2011, 2013, 2017). It is mechanically similar to the "main" game, with most of the difference being found in the setting implementation.
N.B. content organization in Borderline offers a substantive barrier to entry.
From the introduction:
In Adeptus Evangelion, you take the role of one of the few Pilots of the monstrous Evangelion war machines. Given the nature of the battle system described later, it is important for GMs and players alike to note that this system plays best with a number of pilots between 2-4 and a single Operations Director. While number of total players is rarely an obstacle in regular gameplay, combat functions most smoothly with no more than 3 Evangelions fighting at the same time.