While playing a casual run of this game, I wanted to fully complete everything the game had to offer, but I didn't see any guide for it for the DS version, so I had to do it myself, in case that someone would run this game, I want to remark that it seems that there's some extra collectables on this version that weren't present on the GBA version (2 of the ones involves on the side quest), one of them was able to be given, or at least that's what the game tells me, while for the other, I haven't found the NPC, which may not even be on the game.
Another important thing to remark, is that the game, in my case, didn't show 100% completion, but 101%, just in case someone wants to give a try to a 100% run and goes only for 100% instead of the actual full completion.