I loved it!
You took a simple mechanic and infused it with new, creative ideas. What I loved about this was that you added small background elements (e.g., the robots on the horizon, the ships flying past) that established something reminiscent of a story, or at least an interesting setting for the game. It flows well, as there is no narrative to intrude upon the gameplay, and it is quite addictive. The music was a big plus as well- I loved it, and it really helped set the mood for the game.
However, as many have expressed before me, this game can be punishingly hard at certain times. I would have liked there to be levels and a back story. Maybe some more variance in the game, like stairs in the office sections inside the building, or something like that. But that might mess with the flow of it, and it just might not be the direction you wanted to take the game in. Anyways, it was a simple, creative game that had style, and I enjoyed playing it. This is why I love indy developers- for their bold experiments in gameplay. Well done!