These aliens want to eat your house for some reason. You should probably do gun things about it.
Press space to do that thing that I said, and arrow keys to move.
I haven't played every game submitted yet, but it's a safe bet that this is my HANDS DOWN FAVORITE.
Nice way to introduce/teach the one and only gameplay mechanic (beyond walking about) while simultaneously giving us the only motivation and backstory we required.
I played it straight the first go 'round, and once victorious, I shot up the house of my own volition... "know your enemy" and all that....
The second playthrough, I immediately ran around to the back of the house and let the invaders have their way. Surely my eyes were twinkling with glee the entire time. "The old man is not so terribly xenophobic after all." I thought to myself.
I like that you had an uncrossable "property line" in there too. Any sort of commentary going on there?
I guess the state of your house is your only real "score" or whatever. So without the property line, if you value your life, you could just run away and the game falls apart :P. Which in hindsight might have been a better idea..
But I guess limiting the player's freedom gives the old man a tragic flaw or something.