Nyamyam - the team behind 2014's pop-up book puzzle game Tengami - has debuted its next project at EGX.
Astrologaster is a narrative adventure featuring real historical figure Simon Forman, a 'doctor' in the 16th century who solved people's problems and medical ills - from love triangles to syphilis - by reading the stars.
Based on real cases in consultation with historians from the University of Cambridge, the game asks players to use astrological charts to respond to patients.
Each case has four available outcomes based on alignments on the chart, which must be pieced together to interpret what Forman's answer would be.
For example, a woman's husband has a secret, and Forman can use the stars to hint at financial fortunes in her future - or suggest possible infidelity.
Reacting in certain ways sees patients recommend other clients with new unusual cases, all the while a wider narrative sees Forman convince real doctors about his practices.
"It's not really interactive fiction, but it has that element of interactive fiction to it," creator Jennifer Schneidereit told Eurogamer at the show.
"If you wanted to play like interactive fiction and explore the world through the astrology, you can.
"But if you want to use strategy, if you want to see what different strategies exist - because you want to see all the patients, or if you want to get your medical licence - you can also do that. It's up to you how you want to play it."
Astrologaster is set for PC and iOS sometime in late 2018.