Assets:

• Decrepit Dungeon Lite
  • https://assetstore.unity.com/packages/3d/environments/dungeons/decrepit-dungeon-...
• Fantasy Skybox FREE
  • https://assetstore.unity.com/packages/2d/textures-materials/sky/fantasy-skybox-f...
• Grass Flowers Pack Free
  • https://assetstore.unity.com/packages/2d/textures-materials/nature/grass-flowers...
• Mausoleum:
  • https://assetstore.unity.com/packages/3d/environments/fantasy/mausoleum-128753

• Medieval Town Exteriors
  • https://assetstore.unity.com/packages/3d/environments/fantasy/medieval-town-exte...
    
• Mega Fantasy Props Pack
  • https://assetstore.unity.com/packages/3d/environments/fantasy/mega-fantasy-props...
• Modular First Person Controller
  • https://assetstore.unity.com/packages/3d/characters/modular-first-person-control...
• Nature Starter Kit 2
  
  • https://assetstore.unity.com/packages/3d/environments/nature-starter-kit-2-52977
• Realistic Tree 9
  • https://assetstore.unity.com/packages/3d/vegetation/trees/realistic-tree-9-rainb...
• Terrain Sample Asset Pack
  • https://assetstore.unity.com/packages/3d/environments/landscapes/terrain-sample-...
• Water Shaders
  • https://assetstore.unity.com/packages/vfx/shaders/water-shaders-v2-x-149916

BGM/SE:

• Ambient Effects
  • https://mixkit.co/free-sound-effects/nature/
• Music
  •  https://freesound.org/people/CrystalMeshDavid/sounds/442911/