If you missed the metro UI from Windows 8 you can still get it back on Windows 10, here is how:
Right-click the Taskbar and select Properties from the popup menu.
On the Taskbar and Start Menu Properties dialog box, click the Start Menu tab.
Uncheck Use the Start menu instead of the Start screen option. To enable the Metro UI, Click Apply to accept the changes.
The Change Start settings dialog box will appear, to confirm changes, click Sign out and change settings.
Now you have the Windows 8 Metro UI.
To undo Check Use the Start menu instead of the Start screen option. Click “Apply”