gameover.png: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/share/games/oneisenough/bin/pictures/gameover.png - from package: oneisenough

You may install the required package with command apt-get install {package}

Error in other languages:
gameover.png: bevel nie gevind nie
gameover.png: comandă negăsită
gameover.png: comando não encontrado
gameover.png: commande introuvable
gameover.png: command not found
gameover.png: käsku ei ole
gameover.png: không tìm thấy lệnh
gameover.png: komanda nerasta
gameover.png: Kommando nicht gefunden.
gameover.png: kommandot finns inte
gameover.png: komut yok
gameover.png: nie znaleziono polecenia
gameover.png: níor aimsíodh an t-ordú
gameover.png: no se encontró la orden
gameover.png: no s'ha trobat l'ordre
gameover.png: opdracht niet gevonden
gameover.png: parancs nem található
gameover.png: perintah tidak ditemukan
gameover.png: príkaz nenájdený
gameover.png: příkaz nenalezen
gameover.png: команда не найдена
gameover.png: командата не е открита
gameover.png: 命令找不到
gameover.png: コマンドが見つかりません