Due to issues with different aspects of my game in Unity, I decided to switch over to Unreal as I got a lot more documentation and tutorials for that engine as for Unity.
One of the issues are for instance the shader I was using for my terrain that made the textures look better and let me have "holes" in the terrain for my caves. The theory is really nice but over long period of time I did not manage to configure the shader to my satisfaction.
In Unreal, I can do the same thing just out of the box and with simple configurations. On one afternoon I was able to import my terrain into Unreal and set it up that it looked similar to the result in vanilla Unity, I also found a tutorial to get the full functionality of the Unity shader in Unreal.
Unfortunately, I also found a bug in Unreal that removes the textures in the piece of terrain on which the terrain hole is located.
Next steps are to import all the environment assets I used in Unity into Unreal and add them to level. After that I will add the mechanics in blueprints to the Unreal project.
Meanwhile, my brother is working on basic character meshes and a pipeline to provide me with different base meshes for each race that I can then use for my character creation both ingame and for npcs.
All this means, that there will be a further delay in my schedule (which is already about a month behind) but hopefully result in a better base game as well. I will work on key features during the next week and if I run into mayor issues along the way, I only "wasted" a week and will go back to Unity where I have to change the scope a bit and then work on more content. In the event that Unreal helps me catch up lost time and speed up development, I will stick with it and continue working on having a prototype ready for testing a week later.