Hello, I can make the concept game you want.
I could make the art, music, etc to make the game you imagine, or I could also find free for commercial use assets or some already purchased assets.
You'll receive my entire attention and support while the project is in the making and even after the development is done.
I would like you to tell me more details about the game you want, that way I can make an estimate of how many days will the project take to be done, if you need it done fast, I could work some more hours than usual to make it in time. Any idea you have, we (You and I) will find the best way to implement it.
I have 5 years of experience using game engines like Unity3D, Unreal Engine, Godot and BuildBox for game development so it shouldn't be hard to be done in any of these. also have experience in software for 3d modeling, illustration and texturing like Blender, Inkscape, Photoshop and Substance Painter.
I have a lot of experience in game development and I'll do my best to make sure you're satisfied with the results and as I already said, I'll be there if you need help at any moment after the development.
You wanted for us to tell you how to use a prefab, a prefab is a GameObject you want to re use along a project, you can use it placing multiple instances of the object inside the scene editor and also making dynamic instances when the game is running.
Feel free to contact me if you have any doubt because I would really like to work on this project.