The main problem is that it require GLIBC_2.15, while the most updated version for Wheezy is the 2.13.

It is NOT a good solution to install that library using another repository, like "testing", because mixing the distributions like this can create system instability.

So here there is the most simple solution I have found.

We will just use the dosbox version present in the Wheezy repo, and will let it start using the GOG configuration:

1) Download the tarball of the game (I'll suppose it will be saved in the $HOME dir)

2) open a terminal

3) gunzip dragonsphere_1.0.0.1.tar.gz

4) tar xvf dragonsphere_1.0.0.1.tar

5) sudo apt-get install dosbox

6) mv ~/Dragonsphere/dosbox/dosbox_i686 ~/Dragonsphere/dosbox/dosbox_i686_ORG

7) mv ~/Dragonsphere/dosbox/dosbox_x86_64 ~/Dragonsphere/dosbox/dosbox_x86_64_ORG

8) ln -s /usr/bin/dosbox ~/Dragonsphere/dosbox/dosbox_i686

9) ln -s /usr/bin/dosbox ~/Dragonsphere/dosbox/dosbox_x86_64

10) edit, with a text editor, the file ~/Dragonsphere/dosbox/dosbox

you'll have to put a "#" at the start of ALL the lines that are SIMILAR to this one:
"export LD_LIBRARY_PATH="${CURRENT_DIR}/libs"

like this:
"# export LD_LIBRARY_PATH="${CURRENT_DIR}/libs"

now save the changes to the file and close the editor.

11) start the game with ~/Dragonsphere/start.sh

ENJOY the game :)

NOW, at least for me there are some graphic problems while in fullscreen (like double mouse pointer and black lines) and I have to play it in a window (ALT+ENTER)

But I will try to solve those later

EDIT:

found also the solution for my fullscreen problem, I just changed an option in the "~/Dragonsphere/dosboxDragonsphere.conf" file:

from -> fullresolution=original
to -> fullresolution=1024x768