Nice game, good work!
Maybe you could change the arrange of the cards from level to level? That could add some variety to the game.
Also, a nice and small way to make it more connected to the "story" could be adding some phrases for each level and show them according to the actual score (for example, on the first level you could have "I'm not seeing the base at all", "Oh, I think that thing far away is the base!" and so on).