Okay, here's a few pictures of items of interest. We don't see a huge amount of the Aliens in detail so you'll have to fill in the blanks. The good thing about this movie is there were plenty of good old props and models made for it.
City Killer
Captured Alien Attacker (added smooth panels and a launcher for the Nuke)
Alien Attackers (captured Attacker in foreground, enlarge and note the crew lol)
Part suited Alien (woke up during surgical removal of the suit)
Unsuited Aliens in tubes at Area 51
Suited Aliens
Mothership
Troop carriers
Modified Sikorsky S-64 with light bars for communicating with the city killers.