Download it from here (with a browser, it does some redirect crap). Install dosbox:

sudo aptitude install dosbox

It is a self-extracting zip file, so you can either use wine to unzip (holy nuclear option, batman) or install unzip:

sudo aptitude install unzip

Create a directory that we can ask dosbox to mount as ‘C:’, then unzip it:

mkdir -p ~/.dos/Dune2
cd ~/.dos/Dune2
unzip ~/Downloads/Dune2.exe

Get a default config file by starting up dosbox:

dosbox

and (in dosbox) ask it to write out a config file for you:

config -writeconf /home/you/.dosbox.conf

type ‘exit’ in the dosbox window to, er, exit. Add the line to mount the directory we created:

echo "mount c /home/you/.dos" >> ~/.dosbox.conf

and start dosbox again (with that config):

dosbox -conf ~/.dosbox.conf

and run Dune2 in the dosbox window (dosbox’s shell has tab completion, yay):

cd Dune2
Dune2.exe

Clicking in the window will make dosbox grab your mouse and keyboard - ctrl-f10 to escape.