Estranged: Act II
Following on from Estranged: Act I, developer Alan Edwardes announced in 2014 that development on Estranged: Act II had begun. No more details were given, other than that it would be a paid title (Edwardes, https://www.moddb.com/mods/estranged/news/the-next-instalment). Nearly a year and a half later it was announced that for Estranged: Act II, development had been switched from the Source engine to Unreal Engine 4 (Edwardes, https://www.moddb.com/mods/estranged/news/estranged-act-ii-progress). Presumably early development began on the Source engine but no screenshots or media of this iteration were ever released. It was not until 2016 with the release of Estranged: Act II Alpha 1 that any media was revealed (Edwardes, https://www.moddb.com/mods/estranged/news/estranged-act-ii-alpha-1-now-available).
The game was eventually released as Estranged: The Departure in 2017.