Games like Sigma Theory: Global Cold War - Deluxe Edition

If you finished Sigma Theory: Global Cold War - Deluxe Edition, the closest matches are Attack of the Friday Monsters! A Tokyo Tale, Orion: A Sci-Fi Visual Novel, The Martian VR Experience, Boku no Natsuyasumi and Nomad. All 6 share its adventure genre and are ranked by how closely their themes and modes overlap.