Minus a handful of cringe-worthy moments, I wished that every episode of the show could have been 2 hours long instead of 46 minutes, if these are the kinds of stories they could create from the simple time-travel plot device they used multiple times before.
Most sci-fi tends to ignore human nature when doing things like traveling through time and sliding between realities. This was the first time I have ever seen a story portray what would most likely happen in the actuality that someone from another timeline appeared out of nowhere and treated it realistically. We take for granted after a decade of outrageous tales in scientific impossibilities happened all of the time, we just believe it and we're right there with SG-1 in their insistence that the Air Force let them correct the flaw with their own timeline. Alternate General Landry finally put them in their place the way no one has ever done before. It's just a shame that they wrote the lesson out of existence.
All of that aside, the acting was above bar, even for a big budget film. The direct-to-DVD status allowed the actors to act unrestrained, without self-imposed TV regulations, the dialogue was just a brilliant as ever, not only in the clever writing but the carefully crafted alternate timeline with the newly rewritten history and the way it not only showed us something new, but it also meshed perfectly with and even augmented established canon, ex: The 'Gate in the end is transported to the United States with a hole in the box that helds it, as well as the hull of the boat that carried it. It could explain everything from why Dr. Littlefield first activated and stepped through in 1945 to why experts like Captain Samantha Carter and Dr. Daniel Jackson were sought out and brought in, in the first place. Much like the two part Season 8 finale "Moebius", while the events of those episodes are ultimately nullified by the end of the episode, the story told along the way was one of best.
My only complaints were Michael Shanks overuse of profanity and attitude (he seems to have forgotten about his fake leg in the final 30 minutes) and the return of the "Hey you, SG-1, save us please" mentality of the Air Force the moment aliens appear in orbit above earth. After Alternate General Landry's speech to SG-1 about 45 minutes in, I was disappointed to see the Air Force just hand over a wing of F-15 fighters to the people who appeared out of nowhere with strange tales of aliens just a year before. In real-life, if someone magically appeared in the Arctic, accessible only by nuclear submarine and came to the government and told it of an impending alien invasion the government would interrogate the hell out of them and lock them up forever. And if aliens did start invading, the people who knew about it would be in even bigger trouble than before.
None of that was enough to detract from this installment however. I've watched it 3 times since I bought it and I want to watch it again right now. If only because it's the last time I get to SG-1 save the world for a while.