What makes the killing as ethical conundrum thing even weirder is the fact the soldiers are apparently just projections of the protagonist's psyche (or at least that's what he's supposed to believe, meaning even if they're real people or something, he remains innocent of the bloodshed). Heck, I'd say disposing of inhibitions that prevent you from returning to full mental health in a cathartic, violent but not dangerous way is probably a healthy response.
Incidentally, I'd love to joke how the game was "odd" in some way ("it wants to get even 'cause it's odd, hurr-durr"), but given the description it actually feels kinda bland despite being something of a genre mix and match.