A bit belatedly, to respond to Westwall's earlier post extending beyond the realm of the game...
In reality, there would be no rude awakening, no catching up. As the Apes or Angels hypothesis I linked to earlier states, whatever intelligent life we find out in the universe will most likely either be vastly inferior or vastly superior, because the chances of finding a species which fortuitously developed sapience and technology in the same tiny sliver of time (100,000 years) or even in the same cosmic ballpark as us are exceedingly remote.
Those superior, the "Angels", would most likely be hundreds of thousands or even millions (not to say billions) of years older than us as a technological race. And if we ever catch the eye of any super intelligence out there and they mean us harm, there's nothing we can do. Expanding beyond the solar system would only expose us further to detection by malevolent or simply inescrutable demigods.
There would be no XCOM, no Independence Day, no War of the Worlds: they would most likely be able to eradicate us with the flip of a switch. Perhaps even literally. Supernovas or gamma ray bursts on demand. If they feel less destructive, perhaps just a fast-acting super plague engineered specifically to eliminate humans would do. Biological, mechanical, digital or all of it at once, to "format" our planets as easily as we format our hard drives.
Happy times.