Lots of things are not yet in place, and others are only half baked. Most noticable is the complete lack of a technology tree, ship design and tactical combat.
At the moment, we're using a modified version of the Reach For The Stars rules for ships and combat. Basically, there are 4 tech levels that can be researched to produce ships of Mark I through Mark IV, each level of which is about 4x as powerful as the last. Ship combat is resolved automatically at the end of each turn. It might not be as pretty as the real thing, but at least it means that the game is playable. Tech trees, ship design, tactical combat are complicated enough, but teaching the AI to deal with them will be no easy task either. It's on the way...

You can start a new game, explore, colonize, fight and invade enemy planets. You can build factories, bases and ships, and research new tech.

The AI will fight back, though somewhat randomly. They'll beat you if you don't expand fast.

You can't, however, load or save games yet, so probably best not launch off into an all-night session just now.
Drag the map around to move it, zoom in with the mousewheel. Click on stuff to do stuff. Move the game forward with the "Next Turn" button. If you've played the original, it should seem familiar enough.
For fun, notice the "AI Fight" options at the lower right. Click "Fast", tick the checkbox, and watch the game play itself!