I found this game on internet 2 months ago (Gloria Victis), it looks VERY VERY nice , and about the "sandbox" part, I already sold my soul 
. The guys who is developing it , actually, the studio is calling "Black Eye Games" , (is an indie one) they are using Unity Engine for this game, and they don't have million dollars budget, and for this, my opinion, they deserve all respect from every gamer/indie developer . The game will be F2P ( free to play ) .The website address is : http://gloriavictisgame.com/ , there you can find a videoclip about game, and, a very short description.. : " A game developed by gamers, with gamers for gamers.. " Anyway, I will post here the videoclip.
[youtube]http://www.youtube.com/watch?v=hICRzBgx6SI[/youtube]
