I really like Star Realms, at first. It's more of a "deck building" game, like Ascension, or Dominion, than the other CCG's discussed this week. My problem with Star Realms is the balance and games decided early by luck. For instance, there are some cards that are very powerful to buy early, and if that card is available to buy on your first turn, it felt like it could swing the whole game. If it wasn't available for player 2 to buy, well they were out of luck.
I haven't tried the expansion, so I don't know if that problem was addressed. I really wanted to like the game, and I did until I started to feel the outcomes were more decided by the luck of the draw in the first couple turns than by good play/strategy in the remainder of the game.