[amanj41]

There was a Black Mirror episode with a similar concept where footsoldiers were implanted with a chip that made them see enemies as literal monsters

[bawolff]

Its also the plot of a 90s star trek tie in novel for children where they had kids play a censored video game but were really exterminating the native population https://memory-beta.fandom.com/wiki/Highest_Score

Anyways, its a reasonably common sci-fi plot.