Yes it is free. Works on turns, 1 turn per day. I literally spend 5 minutes on it right now to control my 6 planets, I'm sure as I claim more planets it will start to take me more time, or when I get into a war. It is based on a philosophy common in German Board games, so the game is simple yet lends itself to deep emergent game play.
Blacknova traders is a derivative of Trade Wars an old BBS game. Pretty different to this game, which is probably closer to something like O-game, but with less pressure to be constantly online to guard your systems and without the constant upgrading of facilities.
