Steam now offers a playable demo for Agatha Christie: The ABC Murders, a third-person adventure based on Agatha Christie's Hercule Poirot novel The A.B.C. Murders. There's a dedicated page for the demo, but all the descriptions there are from the full game, so here's one of them: "You will have to explore many crime scenes in various cities set in beautiful surroundings across the United Kingdom. Leave no stone unturned when it comes to cross examinations and deadly puzzles! Observe, question and explore everything possible in order to make the smartest deductions and understand the murderer’s plans!" Thanks Frans.