Your job is not only to stop the aliens but to keep people from finding out about them as while. You would do this through a on or off-site facility tasked with keeping the aliens and your soldiers off the internet, off the news, keep witnesses from talking. Also maybe having a branch of the tech tree going into tapping into the alien's communications. This would do two things make the nations like you more(because their people aren't panicking), and keep the aliens from finding out about you for longer. One other part might be letting people find out about you it might lower panic level, but wouldn't make the nations happy and would also increase the likely hood of you getting attacked. Sooner or later the aliens will find you, but you can make it later rather than sooner. Another thing this could impact is how quickly the aliens start equipping better stuff. This would definitely add a whole new level of gameplay that would fit nicely into the game. Plus I also think it would be really cool to get to see a newscast about how your soldiers kick some alien butt and saved the day. Maybe have like a witness talking about how awesome your guys are or some pictures of your soldiers(not screenshots maybe a bunch of stock location generic pictures). Something along those lines.
How quickly aliens equip better stuff should be determined by how consistently active you are if you go and shoot down every UFO you see they will see something is up and start throwing the big guns in faster. Again sooner or later the aliens will start using better stuff, because they don't want to keep losing ships and whatnot. This is kind of going on the assumption that while the nations aren't equipped to deal with the aliens they aren't totally helpless ether. So someone is bound get lucky and shoot down or manage kill the crew of a landed UFO at some point. At the beginning of the game you are only slightly better equipped than everyone else. It would add more randomness to the game by throwing in more crashed and landed UFO missions to the globe. So the aliens would be expecting some casualties. The opening scene where it talks about the first UFO attack it sounds like the aliens landed a small army there because no matter how much better stuff they have five guys can't beat one hundred, unless your playing CoD.
