While "Armageddon" was a great movie in it's own rate, it was more of an action-romance movie that was meant to apeal to a braoder audience and satisfy movie-goers' typical demands of a major release. But with Deep Impact a much different aproach was taken, following in the way of the traditional Disaster Movie Genre.
From the beginning we are introduced to one of the main Characters, an upstart reporter investigating your run of the mill political love affair scandal, but stumbles instead upon the biggest story of history, that there is a monstrous comet on a collision course with earth. And so unfold's the American government's plan to send an team of asteronauts to intercept the comet and plant enough nukes on it to deflect it off course. The movie handles the plot from a much more epic, and at the same time much more personal level than armageddon.
The romance angle of the story is provided by the young boy who unwittingly discovered the comet and his girl neighbor. As counter measures fail, and plan B, C and D are called into action the terrible reality that only so many can be saved, and that it has to be decided who lives and dies sets in. A national lottery determines who will get passage to a special fallout shelter-like cave complex that was built in secret to house 1 million people. The rest are left to fend for themselves.
I really found deep impact to be more emotional, though not as romantic as armageddon. Characters will die, babies will be deperated from parents, young people will be asked to carry burdens that they shouldnt have to deal with and cities are destroyed as part of the asteroid hits the atlantic and causes a massive tsunami. Watching all this really had a more realistic and more message-orientated feel to it than Armageddon. I liked that the movie seemed to follow closer to the science and horrow of what a comet impact could cause, and how that affected the characters and our society. This made the movie much more interesting to me in many ways, and much realer as well.
The special effects are well done enough for the time period, and actually the tidal-wave scene where you watch a city massive wall of water inundate the city, hills and forests was quite ae inspiring. This is well done and will make your jaw drop when you see it.
The only problems are some inconsistant acting, and the fact that this movie is a bit slow and might not appeal to some viewers as much as armageddon because it's not an action movie.
All in all this was a great disaster movie and I thought it did a better job than armageddon in many ways of dealing with the actual plot scenario, though I like that movie as well just for different reasons. But if you're looking for a good sci-fi based disaster movie that will touches on many deeper levels than similar movies than this is your best bet. You're better off renting Deep Impact than you are going to the theater to see "The Day After Tomorrow".