I would like to say firstly that your game is awesome, but the interface have to be more snappy, faster. Another thing abou the UI, I think you have to commit to one art style on your cards, and maybe change the way you select them.

Some alien races to deal with would be awesome too...

I also think that you should put a story in it.

but the game is really really awesome.

Also, if the battles you're planning to put in the game would be in the FTL style, the game would be fucking awesome...

Or in the Rebel Galaxy style I would not complain either, but there is really hard to do something like that.