My answer won't carry much weight on either side as I'm absolutely new to game programming, and I'm plodding along the tutorials in Unity3 comfortably. I suspect, another 3 months on these tutorials and I'll be 1% there to make an informed decision. At the point where I'm at, I just want to use an engine that can incorporate things like what Atavism offers, but with a whole bunch of 'plug and play' options. For example, go to the Assets Store, pick out 6 characters and add them in (with no further coding), etc, etc, etc ... for all I know, perhaps it does this now? I don't know if this exists, but is there a service offered by Atavism that would allow someone like me to select assets, and for Atavism to incorporate it into the game. I mean, I really appreciate the tremendous help and support by staff and non-staff members, but what gets my willy wet, is playing and controlling the game settings with no desire to be a C+ programmer. This probably stems from my years of running a 'Rust' server. Mostly what I want to customise in Atavism, is adding my choice of characters, enemies, buildings and landscape. The game engine itself is superb as it covers a great deal of options in one package. So, if it was a choice between Unity and Unreal, I don't have a clue.