Sea Hero Quest, a VR game built specifically to identify the early stages of Alzeimer’s, has been incredibly effective according to a new study.

In Sea Hero Quest, you navigate a boat. Your objective is to reach different checkpoints with the help of a map, but later on, the map is taken away completely so that you must travel to these destinations on memory alone. This formula has helped researchers and medical professionals identify the early onset of Alzeimer’s in people who haven’t yet experienced major symptoms. 

These mild symptoms aren’t always detectable with medical tests, and according to a study published in the journal PNAS, Sea Hero Quest has been so effective that it is doing better job of identifying them than traditional tests can.

Researchers say that every two minutes playing Sea Hero Quest is equal to five hours of lab-based research. Since its release a few years ago, the data that’s been collected from the game is now equivalent to 1,700 years of research for Alzheimer’s. With over 4.3 million players, Sea Hero Quest is being called “the largest dementia study in history.”

Sea Hero Quest was developed by mobile app developer Glitchers and funded by Deutsche Telekom, in partnership with researchers from University College London, Unversity of East Anglia, and Alzheimer’s Research UK.