Cannot run a program by clicking on its icon whereas it works in command line

Newbie & Debugging Questions
#1

Hi

Somebody tested my Debian packages today. She succeeded in running my game by entering “tuer” in command line but when she clicks onto the launcher in the “Applications” section under Ubuntu 14.04 LTS (with the desktop manager Unity), it doesn’t run. xdg-open just opens the file in a text editor. “gtk-launch tuer” tells that there was an error at the creation of the child process “tuer”, “no such file or directory” and “** (gtk-launch:27745): WARNING **: Couldn’t register with accessibility bus: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.”.

I use this script:

#!/usr/bin/bash
#code snippet written by Dave Dopson: http://stackoverflow.com/a/246128
SOURCE="${BASH_SOURCE[0]}"
while [ -h "$SOURCE" ]; do # resolve $SOURCE until the file is no longer a symlink
    APP_LAUNCHER_DIR="$( cd -P "$( dirname "$SOURCE" )" && pwd )"
    SOURCE="$(readlink "$SOURCE")"
    [[ $SOURCE != /* ]] && SOURCE="$APP_LAUNCHER_DIR/$SOURCE" # if $SOURCE was a relative symlink, we need to resolve it relative to the path where the symlink file was located
done
APP_LAUNCHER_DIR="$( cd -P "$( dirname "$SOURCE" )" && pwd )"
$APP_LAUNCHER_DIR/jre/bin/java -server -Xmx256m -XX:MaxDirectMemorySize=128M -Djava.ext.dirs= -jar $APP_LAUNCHER_DIR/tuer.jar

I know that Ubuntu uses dash instead of bash by default but I expected to get a better error message.

Do you know a possible root cause of this bug? The packages are here:
http://tuer.sourceforge.net/en/play/