This (solo) project is going on since start 2019. I'm using the lua scripting feature of VBA re-recording to modify the game in real time. Is this romhacking ?
No : excepting the use of Drenn's level editor, this is 0% romhacking (deal with it romhacking.net ). But you could say it's ramhacking.
Well,now that I've injected some ASM code into the ROM, yes, it IS romhacking. Not much, but enough to lend me new powers ...
New gameplay mechanics are already inserted (related to enemies, tiles, wario forms, etc). The game progression/events/cutscenes will be completely different.
View the videos below to understand a bit more the project and its advancement.
In order : https://youtu.be/R5mPvP9ANkA
 Introduction, and fiddling with treasure collectionhttps://youtu.be/GYJGHMQobAI
 Slight edit on burnt Wario, and a new minigamehttps://youtu.be/dy8YsCyZugg
 New block(s), vampire wario edit, enhanced warp system, etc https://youtu.be/oaDCqX2z52M
 New enemy, NPC talking and a special inlevel eventhttps://www.youtube.com/watch?v=Zg2J41d_Bac
Wario Land 3 but you beat birds while riding an owl
There are also some shorter videos on my channel just showing one specific edit.
Special shout-out to the warioforums.com buddies.