The horror video game Nevermind wants to get intimate with your wrists. It will soon be able to use the Apple Watch to sense players’ pulses. If you’re wondering why a game might want to know how fast your heart is beating, that’s Nevermind’s hook — it uses biofeedback principles to get scarier and tougher the more stressed you are. It’s like Frank Herbert’s “fear is the mind-killer” mantra, but with digital corpses hanging from trees.

In release notes on Tuesday, Nevermind developers Flying Mollusk also said the game supports “emotion-sensing software.” With this program, a webcam monitors faces for changes in facial expressions and attempts to interpret these as emotion. The Apple Watch complements the emotional switches with physiology.

There’s some evidence that Apple Watch can tell when you’re in a state of higher arousal, cognitively speaking. When Tom’s Guide compared the wearable with medical electrodes, the Watch did middling-to-good, with the caveat it works best when strapped so tight it digs into your flesh. But, presumably, for a game like Nevermind the change in heart rate is more important than accurate readings.

Using facial analysis to determine emotion has been on computer scientists’ minds since the turn of this century.

The software that Nevermind uses is the same software that debuted at the 2013 Super Bowl to tailor advertisements based on viewer expressions. Created by a company called Affectiva, the program stems from academic investigations into emotional recognition and autism.

Nevermind was released in October, and has continued integrating new sensors. Players speak less than fondly of the game’s 3-hour length but totally grok the psychological biofeedback concept.

Photos via Nevermind/Flying Mollusk