I think could be nice view the first game recreate as an romhack for DB-LOG2 or Buu's Fury, but well I guess this can be hard.
The truth is that yes, it would be a lot of work, especially because of the need to change some maps. With that you must know many of the mechanics of the game. I would be lying to you if I said I don't think about doing it, especially when I work at LoG 1, as it can be frustrating at times.
For example, I changed the kinematics of the first screen so that Raditz came to the island flying, Goku preceded him when he went to kidnap Gohan and he fell to the ground after Raditz hit him (as happens in the series) , but I had to discard all that work because somehow, the game keeps the position that Goku was in when the event started and when you take control of the character again, he reappears in that place, and it is very unprofessional.
Another example is that I have prepared different portraits for Goku, the problem is that I had to make his portrait appear on the left and not on the right, a place that the game uses for the rest of the characters. And if to all this you add that I am redoing a large part of the sprites of the characters so that their movements look somewhat better, or simply because of their appearance (I hope to be able to upload images of Nappa soon), because in the end, what turned out to be An easy game to modify has become a little odyssey.
Also I wonder if you have now a tool or what, now looks as if edit these games is easy for you hah!
I would like an "Legasy of Goku 4" haha, based on Dragon Ball Super serie
I don't have any specific program to modify these games, the ones I use are the Tile Molester (God bless its creator), APE, HxD and Paint.
is there any way you could rip the sprites from LOG2 decompressed, like people have done for Buu's Fury? I'm sure there are sprites for characters that are never used in the game, and so they have never been seen by anyone outside of Webfoot, and I'd love to see them if that's even a possibility
In Buu's Fury I have not seen any unused graphics / sprites. There are some enemies with alternate colors that I can't remember where they appear, but I'm pretty sure they do.
As for LoG 2, there is a portrait that is not used, and it is that of Garlick Jr. I suppose they wanted to introduce it into the game but they discarded the idea. Here is the image.
And as for LoG 1, there are some custscenes that have not been used, like the image of Roshi Island or the planet Namek. And I am sure that they also had the intention of adding the Genki-dama technique, since Goku has some sprites raising his arms that are not used in the game and I also discovered some sprites similar to the charge of the Ki ball (can that are the same) used with a bluish color palette that could be the burden of the Genki-dama.