Horizon is a very good space 4X game similar to Master of Orion. Unlike Endless Space, there are no star lanes. Ships have unlimited range and the game is more open. There are up to 10 enemy species, and they act differently. Wars are common, almost from the start.
There are two types of games. Normal mode is the campaign, were everyone else starts with a lot and there are missions to perform as the humans. Classic mode has everyone at tech level 1 and with only one world. I've played classic twice now and had fun.
Horizon is a little challenging, especially at the start of a new game. Oh, in classic mode you can elect yourself as Leader of the Galaxy.
This game is still in beat, but has a great development team. I've already exchanged email with the lead programmer. Anyway, I love it!