That version of snake was actually from the early development phase of the PC port from 1999-2000 where higher-res textures were used, but Kojima himself did not like the change so they went back to the old textures.

Here's more info: https://www.reddit.com/r/metalgearsolid/comments/3abf2v/interesting_details_on_how_the_mgs_pc_port_was/

what about the early solid snake that had a face