There's a freeware game called "The Road to Druaga" that's based on the Tower of Druaga series. You can find it here: http://druaga.onoda-pro.com/
However, unless you're playing using the Japanese locale for Windows 10, the game will just show a black screen.
You can always switch your locale to Japanese, but that can cause problems with other programs. You can also load up windows 7+ in Japanese locale in a Virtual Machine.
However, I chose instead to use a program called Locale Emulator, which you can find here:
First, you need to extract the files from The Road to Druaga zip file, with the filenames intact. Unfortunately, the filenames are not using unicode characters, but are instead using shift-jis(I assume).
In order to extract the files with filenames intact, I used a 32-bit version of 7-zip, which I installed from here: https://portableapps.com/apps/utilities/7-zip_portable I used the portable version so it wouldn't interfere with my current install of 7-zip, which didn't work with Locale Emulator. I don't know why it didn't work, but I assume 64-bit apps just don't work with Locale Emulator.
I loaded the 7zFM.exe as Japanese using the right-click explorer extension for locale emulator. I then found the Druaga zip file in the file explorer. I could see the filenames were intact, and when I extracted the files, the filenames were still intact.
I then ran the Druaga exe using Locale Emulator and it seems to work with no issues.
The game menus seem to be in English so I had no problem navigating them.
The readme text file, in the folder, is also in shift-jis so in order to read it you need a program that can read shift-jis. One program that can do this is JWPce http://www.tanos.co.uk/jlpt/extras/jwpce/ but you can also just load the file with locale-emulator. When I opened it with locale emulator it opened in notepad and it displayed correctly. But the entire readme is copied on the download page http://druaga.onoda-pro.com/download where you can conveniently use google translate.
I would share the files with filenames converted to unicode, but I don't have permission, and the readme strictly forbids redistribution without permission.
It's been brought to my attention that instead of using locale emulator with 7zip(or some other zip software), you can use Bandizip from https://en.bandisoft.com/bandizip/old/6/. I used the 6.27 portable version because it's ad-free and doesn't require an install. When using Bandizip, you select the World symbol on the toolbar, and select Japanese.
You'll still need locale emulator to play the game.