This artwork was commissioned by me and drawn by Marker Slayer.
I have permission to distribute this work.

So yeah, this skin is based on the aesthetics of Aperture Science from the Portal games. Doomguy has a hard-light Doomblade, a shoulder launcher inspired by the classic Portal Gun, and a helmet designed after a Personality Core.

As a side note, there's an FPS called Splitgate that combines traditional multiplayer shooter gameplay with portal guns, and it's kinda popular lately. No real connection to this drawing, just thought I'd share.