itch.io

No external app needed (well, you can use the itch app for auto updates, but that's not required). It should just open when you run the exe, but sometimes that doesn't work on some PCs. To fix it, try this:

Create a new text file inside the folder you extracted the game in, name it however you want, then open it and paste this:

"Deltarune Lightners Live Plus.exe" --rendering-driver opengl3

Change the file extension from ".txt" to ".bat".

Now open the ".bat" file, which should run the game

If that still doesn't work, look in the command prompt window that will have also appeared when you ran that ".bat", and see if it outputs any errors when it crashes. Ignore the 3 red extension errors, and 1 yellow icon warning, they're known and shouldn't ever cause it to crash. But let me know if there's other ones, since that could explain the cause so I can fix it.