What I did was go to the badmojo.exe and set the compatibility mode to run in 640x480 resolution. It still doesn't run exactly full screen when playing videos, but they fill up more of it. The game runs completely full screen, though (aside from two minor bars on the top and bottom).

I tried setting the resolution at 640x480 and the game just crashes at start up :(

You need to set the resolution to badmojo.exe as said, AND start the game from launcher.exe (or the gog installer shortcut), it's working for me.

This isn't working for me.

I followed the same steps--setting badmojo.exe to 640x480 via the Compatibility tab, then launching the game via launcher.exe--and this is what I get each and every time I try to launch the game:
(see attached image).

I'm running on Windows 7, 64-bit.

If anyone knows of a solution to this problem or a better way to accomplish full-screen, please let me know.

I set the resolution on Launch Bad mojo.exe, not badmojo.exe. It's work for me. Maybe it will help you.

I have tried turning to 640 compatibility mode, My problem is my monitor does not go that low. so it emulates it still in the small box.

Anyone figure out another way besides compatibility mode 640?

That helped, but I have much larger black bars on both sides (not visible in the screenshot for some reason).
That doesn't matter too much, I don't know how a 2D game with pre-rendered backgrounds could be run in widescreen (16:9) without stretching the picture.

http://i.imgur.com/TcJrgGv.png

place the dxwrapper.dll in the game directory
https://github.com/elishacloud/dxwrapper