One of my dream projects for a long time has been to do a fan remake/upgrade of this game that retains all the good stuff and the original spirit, but has big QoL improvements and a boost in the audiovisual department (I also want to do one of Super Butoden but I'm NOT a good enough programmer to do a fighting game, heh.)
Here's what I've got so far:
Graphics:
My main focus right now is to improve the map and battle sprites by beefing up the color palette a bit, reducing the black outlines and giving characters actual eyes instead of looking like they've been mimicked by a Ditto. I'm also experimenting with some motion blur frames to add a bit more impact to hits.
http://rosiero.com/misc/ssdr/ssdr_goku.gif
^ Goku's battle sprites.
http://rosiero.com/misc/ssdr/map_goku_02.gif
^ Goku's map sprite.
http://rosiero.com/misc/ssdr/ssdr_prev_bat.png
^ Battle sprite idle poses for the other playable characters.
Music:
I'm not 100% sure what I'll do yet, but here is a proof of concept of a remixed battle theme:
http://rosiero.com/misc/ssdr/ssdr_battle1.mp3
It uses samples from the Super Goku Den games. This was made in FL Studio with the C700 VST, which mimicks the SNES's music chip, so this should sound faithful to the hardware, but I'm not an expert in that regard.
In general, I intend to remix all of the existing songs from SSD, extending the very short ones in the process, as well as add a bunch of new tunes to create more variety. Battles especially need more music; expect boss music as well as varied tunes for random encounters depending on the type of enemy you're facing, a la EarthBound.
Programming:
It's still early days, since a lot of backend stuff needs to be done before you can get anything on screen. I'm programming this in Game Maker, since I'm already familiar with it and I'm fairly certain this type of game won't run into the engine's limitations.
http://rosiero.com/misc/ssdr/ssdr_teaser.png
Right now I've got a test battle screen that looks like this; I've got a few of the battle animations implemented.
Thanks to Fionordequestor's big thread on how to speedrun the game, I can use the original damage formula, but other than that I kind of have to guess at how the game's internal math and RNG works. It's probably more important to make sure it's fun rather than 100% accurate to the original, but I tend to worry a lot about these things.
Planned QoL Improvements:
I want battles to be MUCH faster than they were originally. Not only speeding up the animations a bit, but making everything flow by using less on-screen text when visuals can convey the same thing and having the animations be as continuous as possible, instead of everything resetting after each exchange.
Meanwhile, on the map the controls will have some basic simplifications; a single button can be used to fly and land, and one button handles both the "look" and "talk" commands. The encounter rate will also be lowered and checked in such a way that you can't immediately get into a battle the instant you move, which was a frequent occurrence in the original game.
Planned new content:
Once the original game is fully implemented, I want to add a bunch of new content; the NES games that SSD sort of remakes had a bunch of extra stuff, like the Earthlings going off to find the Dragon Balls to wish Goku back and fighting Garlic Jr. along the way. It would also be super cool to adapt the Cell arc, since I can think of a ton of possibilities for the player to alter the story there.
Of course, this is all going to take a REALLY long time to do. I've got a full time job and another, original game project I'm working on with some folks, while this is a free-time project I'm doing on my own. I'm also not the greatest programmer, so I fully expect to get stuck on something stupid for a while.

What do you guys think? Do you have any suggestions for what I should do? Let me know! ^.^