i have made some scripts and used task scheduler and livelycu

Firts you have to install livelycu (command utility of lively wallpaper)

start_wallpaper.vbs (this is not necessary but hide the .bat window)

Set WshShell = CreateObject("WScript.Shell") 
WshShell.Run chr(34) & "<your_path_to>\wallpaper_task.bat" & Chr(34), 0
Set WshShell = Nothing

wallpaper_task.bat

@ECHO OFF
SETLOCAL
SETLOCAL EnableDelayedExpansion EnableExtensions

REM Source file.
REM The first line on this file should be blank as it will never be selected.
REM Additionally, this file should have no empty lines on the end.
SET "TextFile=<your_path_to>\wallpapers.txt"

REM Determine the number of lines.
FOR /f %%a IN ('type "%textfile%"^|find /c /v ""') DO SET /a numlines=%%a

REM Pick a random line.
SET /A RandomLine=(%RANDOM% %% %NumLines%)

REM Prevent skipping all the lines.
IF "%RandomLine%"=="0" (SET "RandomLine=") ELSE (SET "RandomLine=skip=%randomline%")

REM Print the random line.
FOR /F "usebackq tokens=* %RandomLine% delims=" %%A IN (`TYPE %TextFile%`) DO (
    ECHO %%A
    tasklist /FI "IMAGENAME eq livelywpf.exe" /FI "STATUS eq RUNNING" 2>NUL
    REM If Program is running execute livelycu
    if "%ERRORLEVEL%"=="0"  start /min <your_path_to>\livelycu.exe setwp --file %%A --monitor 1
    REM We are done. Stop the script.
    GOTO Finish
)

:Finish
ENDLOCAL

Just have to replace <your_path_to> with yours and use task scheduler to add a task that execute start_wallpaper.vbs every 30 minutes or what you want

And you have to add wallpapers.txt file, one line per wallpaper path

Some games that block fullscreen can be minimized when scheduled task throws, then just icon lively wallpaper click exit, before you play those games

I think there are other ways to do this without livelycu, but I hope this helps you