I think the idea still has merit, but has some kinks that need to be worked out.
(says the guy who only posted one time)
I think one of the problems was that, apart from the main villain, there weren't really any details when it came to the bad guys. Like, it was an alien invasion, yeah, but there weren't any specifics on what kind of stuff they had, if there were mini-bosses or whatever along the way, that sorta thing. It's kinda hard to just say "he fights some bad guys" over and over and keep it interesting.
So I think one thing that could be a huge help in getting the party moving would be a clearer demonstration of what we're up against. Not to say spell everything out, but throw in some officers or lieutenants among the rabble, show off some special abilities, so we have a clearer picture of what they can do, and what we can do against them. That'd give us a lot more to work with.