Looking for a gruesome device for your big bad villain to deploy in a modern horror or James Bond type game? Or perhaps to use as a mechanized death ritual in a futuristic post-apocalyptic setting?
The Euthanasia Coaster might fit the bill. It’s a hypothetical roller coaster designed to kill by high G-force induced cerebral hypoxia - extended lack of oxygen to the brain. Riders would experience 10 Gs of force for over 60 seconds, quickly going from tunnel vision to blackout to death.