Okay, to start off - I first watched this movie at the age of 5. I rewatched it a few times over the years, and now at the age of 22, I still love this movie.
Let's face it, not everything from the early 2000s was good or aged that well. This movie aged really well! I still laugh at all the bad jokes every time, the silly puns, and still love the story.
Story: This is a good spin off from the original Digimon series, and fits in well with the events that went on. It does a good job to connect to the
series. I do have to say though, you you watch this as the US version "Digimon: The Movie", right after watching the original series, the timeline of events will never quite add up. So just enjoy it as a standalone piece.
Did you like Summer Wars? This is very similar, but we're set a couple years back (In a time where a dial-up connection could stream crystal clear quality video to a million people, apparently). Also the military did not care if you used their satellite connection back then.
Art: Fairly good for the time it was made, I feel, although not 100% up to par with the original anime. If you continue onward to watch the second Digimon movie, you'll think it's fantastic because the art is pretty rough in that one.
Sound: I actually feel this movie is best watched as an English dub - the jokes are funnier, the soundtrack is really good and reminiscent of all those songs we loved in the early 2000s (Smash Mouth, the Barenaked Ladies).
Characters: They did not change between the series and here, so it's all good.
Enjoyment: Seriously, this movie cracks me up every time I watch it and makes me smile. It might be old, it might not be perfect, but it is just super fun to watch every time.