I mean, I like Zack and Cloud just about as much as the next guy, but goddamn, it would've been really boring to play. To me, it's something that seems far more suited to fic than to action/adventure gameplay.
Combat wise I'm not sure what would have changed really. It's still one person fighting monsters. The only difference is that there could be more diversity.
I mean, he dragged Cloud from Nibelheim to Midgar. Think of all the places they could have made him gone through. Cosmo Canyon, North Corel/Gold Saucer, Junon, Chocobo Farm or the marshes, that place with that really annoying mini game with the phoenix materia I can't remember right now. You could fight a Zolom as a boss, or make you sneak through Junon past all the Shinra soldiers. Ride a chocobo, or have a chase scene.
It's not like you can't get MORE repetitive than the amount of side missions they throw at you. I enjoyed them well enough but after awhile, everything is monotone. You could have halved the missions, there would still be plenty, and give some of the rewards to the main mission.
Really emphasize Zack's isolation and loneliness during that time with a comatose buddy being his only companion -- sort of his Wilson, if you will.
This. They missed a good opportunity to really build a feeling of isolation that would have stuck with the player.
I suppose though, there's only so much you can do with a small budget PSP game.
1) Unlocking a DMW Theatre so you can rewatch all the DMW cutscenes at your leisure
2) Having more DMW scenes
I felt like the DMW was there specifically for the ending scene where it breaks down. Honestly I didn't feel much about the DMW other than it was a little clunky, not terrible, but an odd addition to the combat. I didn't particularly care for it, some of the scenes were nice but I don't understand why they didn't fit it somewhere else rather than break up my combat.
And then the final fight and I was like, ah yes. I get it now. Playing through a broken DMW was actually quite powerful imo. Wish it was more fun before that though.