It's a 12+ rating (presumably for a reason). It's all boobs and bum and weapons/shooting. My gut instinct is that it's not right/healthy/appropriate for a six-year-old boy, albeit a fairly mature one.
I've tried to reason with DS's dad, who thinks it's fine for DS to play this game. His dad also has a lodger who's into computer games and DS said yesterday that he'd had a bash at a 16+ rated one with him. 
Am I having an OTT drama about something fairly benign here, or is this not on? And if I'm not being unreasonable, is there anything I can do about it?
Thanks.