plt-games: command not found

Have You tried accessing the binary with the full path?

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/bin/plt-games - from package: racket

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