This movie is a pretty decent modernizing of the original 1985 movie. It has some great gains that would have been difficult to produce 35 years ago, yet in some other areas it really lacks in comparison to the original. The starkest difference between the original and the remake is that the original had a lot more of a comedic color to the entire movie while the remake was a lot more serious and captured realistic emotions of the main characters. If you really enjoy Doraemon for its (old-fashioned) comedy, the original is probably your cup of tea. If you enjoy watching Doraemonand the gang overcome dramatic episodes, the remake is probably for you.

The storyline was simplified to get the movie flowing a little faster, which seemed to work really well. The production team did a pretty good job of eliminating unnecessary sci-fi details and exposition scenes that turned the focus away from the adventure. They also flipped the sequence of some scenes around but that improved the flow. The scene of Doraemon and the gang splitting into two groups was especially effective, clearly showcasing the emotional state the main characters are in during that moment.

As a fan of Doraemon for its comedy, I couldn't help but notice the weak spots in the comedy arena of the remake. Most noticeably, Rokoroko was a lot less talkative even though the movie still attempted to portray him as such. He ends up being only a repeated gag point with only a couple minutes of shining moments. This is still true of Rokoroko in the original movie, but it fit more nicely in the overall comedic feel of the movie.

Even the drama had some confusing moments. We never really understand what kind of person Piina is and how the sibling relationship between her and Papi enhances the story. She just seems to be there only to raise the stakes in Papi's decisions, but his resolve can only feel so deep when his background was not so deeply explored either.
Papi also has some contradictory moments. He mentions more than once about what friendship taught him and how being able to lean on others feels great, but he ends up doing a lot of things on his own without telling Doraemon and company. Papi, as a result, feels really close to Doraemon and the gang yet really distant from them simultaneously.

Finally, Suneo's internal conflict felt better executed in the original than the remake. Suneo's feelings flips 180 degrees multiple times throughout the movie, which felt pretty extreme. I don't remember Suneo being that wishy-washy in the original.

This is not to say the original was flawless. The original had its fair share of really weak spots. When I watch remakes, I tend to look for whether those weak spots were fixed, or if they were able to shift the focus so those weak spots aren't as problematic. While visual, directional, and story improvements were made really well to enhance the original story, the remake was unable to dive deeper into important characters to strongly signify what was at stake in the movie's main conflict.