A couple of minutes in, I found out that this was actually meant to be a highlight reel from some of Full Moon's alien-based movies in the past. Except at 3 hours long... it's a lot more than just the highlights. You actually almost see enough to follow some of the stories for the films, but because they basically just jump around to the action scenes, you miss all the rest and just get exceptionally unsatisfying versions of a bunch of different alien movies.
It's kind of like watching one of those movie trailers that gives away every plot twist and scare shot in the movie... only there are about a dozen of them back to back, and they're all about 15 minutes long.
The only redeeming qualities are the few extras and the fact that Full Moon has such a large catalog represented here, it's bound to lead you to a movie that you'd actually like to see. That's not quite enough for me to suggest this to anyone else though.