Realmz made me come here .... holly crap <3 dude are you still working on it ?
No, Suzerain is complete (and has quite a dramatic ending, if I may say so).
Of course there is more that one could create. I originally considered having the game take place on multiple planets, but that was a bit too ambitious.
If you (or anyone else reading these comments) have purchased the game and are interested in altering/improving/adding on to Suzerain, let me know and I'll send you the source code & all of the assets.