Thanks !
I can't wait to see your next update !
I am using only paint and gb studio 2.0
I had some difficulties for the Jump movement (I tried to modify it)
In your project it worked very well.
In my case, after modification, depending of the scene, jumping can make some bug (Luigi trapped definitively between 2 collision even if the boolean variable is true or false or in front of some ennemies...). And jump over ennemies make some issues on top down scene.
So for the jump, I will let like you did, it is better and more efficient. I just replaced the hammer by a big punch with a "pouf" sprite in order to have an attack Item colliding on ennemies and avoiding ennemies touching player (when ennemies touch player, player is hurt)
For the castle, garden and the battlefield, I was inspired first by your project and also by old top down plan view in several web sites of SM64 game.
Very hard to reproduce that with paint and almost by unique tiles limit (192).
There, my first beta garden (don't pay attention at the monsters ...)