Simple Question

[HikenNeo]

How do i add custom houses, trees and etc. on a map?
I know how to make an simple map by using the AdvancedMap editor, but the tool only has the default stuff of the game. I wanna know because i recently played Pokemon Hoenn Adventures and Pokemon Lion Heart and those hacks have amazing map sprites

 

[Uncommon]

This is my favorite resource on this topic: Le Pug's Tile insertion guide

This one is also excellent: Cello's Tile insertion guide

Some of the tools they mention might be outdated, but these will give you a very detailed understanding of how this is done.

 

[xCeeTee]

Is it possible to put in challenges like a hard mode? Or would I have to create a separate rom hack for that? This is much unlikely, but has anyone made a hack where you can choose to run a challenge like no healing items, and the even more unlikely nuzlocke?

 

[Avara]

RE a Nuzlocke mode I think there are some Gen I or II hacks that have done this, but I don't know any Gen III hacks that have off the top of my head. If this would be something the player would choose at the start of the game I imagine you'd need quite a bit of ASM for that (or depending what it is you're setting out to do, you could make a separate "harder" version of your hack, I remember a few people doing this).