More reasonably even, if we look at Sunk Cost Galaxy and other insider info, SC dev in 2012 was only a kind of proof of concept made by Crytek with no actual gameplay (more like a machinima actually). Actual dev started around the end of that year IIRC when the CiG / RSI structure was set up, with the transfer of that code base and later on employees. Which is the reason of that game engine choice (which was not a choice, then) and the very much "FPS oriented" kind of movement / gameplay.
That is kind of funny, because yeah, we only know that because of things we have learned from sources other than CIG. While back then, CIG were selling SC as something they had been working on already for a year and what they showed off was "actual game assets in game engine" and i'm pretty sure based on that and other marketing by CIG at the time, people were led to believe CIG already had a basic working game which just needed expanding upon. You can see this in some of the early discussions about SC.
Interesting to note then how the narrative changed by backers over the years to come to represent a start date more closely matching the actual start of "real" development, which CIG had a dozen people and a dozen third parties helping with development... well, at least until the massive mess they had with Ilfonic and Star Marine.