Source (link to git-repo or to original if based on someone elses unmodified work): https://cihangircagatay.blogspot.com/2020/09/alien-gnome-transformation-pack-for.html#more
Single command auto- installer, complete transformation pack from Ubuntu desktop to default Gnome desktop including all gnome core applications right after next login.
Extra beautiful 4k Ultra HD desktop wallpapers, animated cursors, my Adwaita default folders blue version, gnome login and boot screen logos, Custom blue Gnome (about) logo,Gnome extensions and much more.
Extract the contents to somewhere and navigate to the downloaded folder in terminal and type:
"sudo sh install.sh" (without Quotes.)
(Due to your system updates sometimes you may need to repeat this)
Check out "Help" folder for advanced customisation.
You may want to delete manually Ubuntu background images inside "/usr/share/bacgrounds" and leave "gnome" folder as stand alone by itself.
You may also want to delete manually Yaru themes inside "/usr/share/themes" and Ubuntu & Humanity & Yaru icon sets inside "/usr/share/icons".
And finally you can freely uninstall your pre-installed Ubuntu apps corresponding with the defaut Gnome apps such as Rhythmbox, Evolution, etc. If you wish.
I'm not responsible for any probable damages on your system so use it with your own risk, it works fine on my system however.