I got burned out mounting dos games manually, so I decided to create icons on my desktop that launches my DOS games purchased from gog. Here is how to do it...for the people that are new. I use Mint with Cinnamon, but you can apply this guide to Ubuntu. DOSBOX is a native Linux program, so it is better to run that as opposed to running it through WINE.

1) install DOSBOX from the Software Manager
2) install all DOS games with either WINE or Windows. This is temporary, and only to copy the actual game folder. You can uninstall after you have a copy.
3) Copy the game folders to a folder in your home directory. I called my folder dosgames. /home/username/dosgames. I also renamed my game folders with dos friendly names like MOM for Master of Magic.
4) the games comes with DOSBOX confirg files, but I just made copies of the default one that comes with DOSBOX. You can find them in the .dosbox directory inside Home. This is an example name: dosboxMOM.conf
5) Each independent game config file needs to have mounting information and exe location at the bottom like this:

[autoexec]
# Lines in this section will be run at startup.
# You can put your MOUNT lines here.
mount C ~/dosgames/MOM
c:
MAGIC
exit

6) Next create a launcher on your desktop called MOM and add this in the command:
dosbox -conf .dosbox/dosboxMOM.conf
7) The final optional step is to change the icon, and I used the icon that came with the game and made a copy of it. I had to rename my copy with a .png like mom_icon.png so that I could choose the file.

That is how I make custom icons on my desktop that launch each game that I buy from gog.

Dungeon Keeper requires a CD mounted for CD check. This is how you address this issue at the bottom of your DOSBOX config file for that game.

[autoexec]
# Lines in this section will be run at startup.
# You can put your MOUNT lines here.
mount C ~/dosgames/DK
c:
imgmount d "GAME.INST" -t iso -fs iso
cls
Keeper.exe
exit