[Alt + Enter] can be made to work...

[Hyperduel]

Just use dgVoodoo2 and set the options for this game to the following...

https://i.postimg.cc/P5ScGvh3/dgvoodoo.png

Specifically, the two "Behavior" options need to be both unchecked for it to work.

Now you can switch back & forth between full-screen and windowed mode if you have to get back to your desktop momentarily.

I haven't found a way to get [Alt + Tab] working unfortunately...after numerous attempts using various wrappers. It crashes out every single time.

But at least this method above is available

NOTE: If you don't know how to use dgVoodoo2, just place all the .dll files from the MS/x86 subfolder into your game folder, as well as the control panel file (dgVoodooCpl.exe) to adjust the options.

Download: http://dege.freeweb.hu/dgVoodoo2/dgVoodoo2/

[Sysgen]

Thank you

[midori]

I find borderless gaming is perfect for this game honestly. Easiest thing ever to use too. Just get the free version on github then you can alt tab, run in full screen windowed etc.