Hi, Maybe somebody can add/update games-strategy/unknown-horizons for 2013 version, I fount only 2012.1 in gamerlay overlay.
https://github.com/emcek/gentoo.mipl/blob/master/games-strategy/unknown-horizons/unknown-horizons-9999.ebuild you need fife-9999 and fifechan-9999 from bug 310155 as well
Created attachment 378708 [details] live ebuild
Gamerlay ebuild is broken (I wonder if I need another bug report for this) with the same description as here: https://aur.archlinux.org/packages/unknown-horizons/
emc overlay has now a working ebuild for git version. https://github.com/emcek/gentoo.mipl/blob/master/games-strategy/unknown-horizons/unknown-horizons-9999.ebuild
a bit newer version 2017.2: https://cgit.gentoo.org/proj/gamerlay.git/tree/games-strategy/unknown-horizons https://cgit.gentoo.org/proj/gamerlay.git/tree/games-engines/fifechan https://cgit.gentoo.org/proj/gamerlay.git/tree/games-engines/fifengine