The game referenced in the engravings, Helldivers 2, is in the mold of Starship Troopers. The underlying joke or trap of the game is to see if players notice that they are enthusiastically fighting for a fascist regime - in the same way that the "good guys" in Starship Troopers are explicitly portrayed as Nazis.
Like most of what we've found out, the shooter is engaging with heavily ironic internet content that is very typical of both far-right and left internet subcultures that congregate on platforms like Discord.
https://www.pcgamer.com/games/fps/the-united-nations-asked-helldivers-2-studio-arrowhead-if-itd-give-a-talk-on-psychological-manipulation-could-we-brainwash-an-entire-community-to-fight-for-a-fascist-state-would-we-be-okay-with-that-turns-out-yeah/
Of course, you might start to wonder how fun it’ll actually be once you consider the implications of dressing players up in fascist uniforms and calling them to arms under the banner of an imperial state to die, die, and die again in the name of democracy. "We asked ourselves, could we brainwash an entire community to fight for a fascist state? Would they? Would we be okay with that? And turns out, yeah, actually," Pilestedt said in his talk.