I don't find there's a hell of alot of upgrades and research and the game can be pretty short (If you do it right)
It's extremely hard to keep every country intact. Also you won't get random abduction fights when you have a satelite over a country so once you have them all up they stop completely. Still a lot of other events though. And the enemies seemed linked to your research and equipment so if you keep things low for awhile you can get quite a few sats up. I only need 2 more and have only had one country leave so far. Having a blast with it. Again.