To be precise, the main storyline is complete. There's still the side stories to deal with, but they're just fun extras. I've now read through the entire plotline and understand all the mysteries of this world. Of course I'll work on the side stories from here, but this is still a milestone.
Considering how long I had to wait to receive the answer to the mysterious puzzle first posed in the D.C. III anime over four years ago, I'm just relieved it's finally over.
Aoi's route was okay -- it revealed half the mysteries so was cool in that way -- but I'd never choose her in the real world. She's just this hardworking, serious type I have nothing in common with. I'd even prefer Charles if it came to that.
The real gem was the 'Da Capo' route, which solved the remaining half of the mysteries, featured a lot of Sakura, and made you feel like your effort in all the other routes wasn't wasted, by having all of it come to bear at the final moment, both in 1951 and in 2051.
Now that I've seen the whole story, even more I wish they would go ahead and animate the rest of the story. Da Capo III is a masterpiece. It's better than Da Capo I, though nothing can beat II. The game totally justifies its franchise ranking as #2 best visual novel series ever, behind only Clannad.
The game was originally rated PG-13, so you could leave out all the ecchi stuff without harming the plot in any way. The anime would work just fine adapting the original visual novel. It would probably have to be 2 cour to work, but it's not a story that doesn't adapt well to anime. There isn't a lot of stream of consciousness monologues, for instance, which is what made the Planetarian adaption such a hopeless endeavor. Nor is there a bunch of violence, which kept Rewrite from being adapted properly. And because the Da Capo arc explains in-game all the different routes, there isn't even a need to somehow collapse all the various routes together into one common route, you can just properly follow the game's plot and tell everyone's stories accurately.
If there were such a wonderful Da Capo III anime, a proper sequel to the prelude anime we received, it would be a tremendously good show. But since there isn't, I suggest everyone start the drudgery of clicking through the entire visual novel instead. This is a can't miss story, especially if you've already embarked upon its mysteries via watching the anime. Four years of agony finally turned into pleasure. Why wait any longer?