Unity 3D on Fedora 31 Linux distro.

First, you need to have good hardware to run the Unity 3D software on Fedora 31 Linux.
To install on Fedora 31 Linux is easy to do. You need to download the Unity beta application from this website.

[mythcat@desk ~]$ cd Downloads/
[mythcat@desk Downloads]$ chmod +x UnitySetup-2018.2.7f1 

You need to install this package for this file: libgconf-2.so.4

[root@desk Downloads]# dnf install GConf2-devel.x86_64

The next step is simple run the installer and follow the interface...

[mythcat@desk Downloads]$ ./UnitySetup-2018.2.7f1 

If you want to use a free license then you need to save the license from application into the file named Unity_v2018.2.7f1.alf .
Using the Unity website manual activate the free license and download the file named Unity_v2018.x.ulf. You can use the UnityHub.AppImage from Unity official website to install any Unity 3D version:

[mythcat@desk Downloads]$ chmod +x UnityHub.AppImage 
[mythcat@desk Downloads]$ ./UnityHub.AppImage 

See the screenshots:

Lutris the Open Source gaming platform for any Linux distro.

Lutris is an Open Source gaming platform for Linux. It installs and launches games so you can start playing without the hassle of setting up your games. Get your games from GOG, Steam, Battle.net, Origin, Uplay and many other sources running on any Linux powered gaming machine.
You need to create an account and you can run many games on Linux and multiple platforms, see the official website with games.
If you want to install it with your Linux distro the take a look at the official webpage.
I used the installation process on Fedora 31 with DNF tool:

[root@desk mythcat]# sudo dnf install lutris
Last metadata expiration check: 0:06:35 ago on Wed 04 Dec 2019 07:15:23 PM EET.
Dependencies resolved.
======================================================================================
 Package                    Arch       Version                      Repository   Size
======================================================================================
Installing:
 lutris                     x86_64     0.5.3-1.fc31                 fedora      2.0 M
...
Total download size: 129 M
Installed size: 708 M
Is this ok [y/N]: y
...
  llvm-libs-9.0.0-1.fc31.i686           ncurses-libs-6.1-12.20190803.fc31.i686       
  python3-evdev-1.1.2-4.fc31.x86_64     unixODBC-2.3.7-5.fc31.x86_64                 
  vulkan-loader-1.1.114.0-1.fc31.i686  

Complete!