Something much smaller for sure!
I'm already making a 2d project actually, so I'm just looking into it while I take a break.
I've always liked the idea of making a billboarded first person RPG though.
Thanks.
Definitely doable. This template already has multiple principles working for something like that. It would have to be heavily transformed though, like getting rid of the level structure and using more open ended connected rooms instead.
My advice to you would be to also look into .obj import. DragoniteSpam on Youtube has an excellent tutorial on it! With that you can include very complex 3D models as well (like pre-made houses and stuff).
As for billboarded sprites... The 8 directional type works so nicely for games in this style, but drawing them can be really hard. The original Doom for example used sculptures that they photographed from multiple angles while using something like stop-motion before converting them into sprites. I would love to figure out a nice trick to do sprites like that myself :D