konquest: 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 CentOS possible default full paths are:

/usr/bin/konquest - from package: kdegames

You may install the required package with command yum install {package}

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