[Pedido] Memory

os.execute("title Memory Game (From Lautenschlager)")

system = {}
system.sleep = function(time)
    local timer = os.time() + time
    while timer > os.time() do
    end
end

summon = function(dif)
    system.sleep(2)
    os.execute("cls")
    local i = {"<","<",">",">","<","<","<",">",">",">"}
    local c = 8
    if dif >4 and dif < 10 then
        i = {"<",">","^","<",">","^","<",">","^","<",">","^","<",">","^"}
        c = 18
    elseif dif > 9 and dif < 15 then
        i = {"<",">","^","@","<",">","^","@","<",">","^","@","<",">","^","@","<",">","^","@"}
        c = 48
    elseif dif > 14 then
        i = {"<",">","^","@","!","<",">","^","@","!","<",">","^","@","!","<",">","^","@","!","<",">","^","@","!"}
        c = 78
    end
    dif = dif + 3
    os.execute("color "..c)
    local sequence,done = {},0
    for v = 1,dif do
        table.insert(sequence,math.random(#sequence+1),i[math.random(#i)])
    end
    while done <= #sequence do
        local sq = ""
        for i = 1,done do
            sq = sq .. "  " .. sequence[i]
        end
        io.write("\t\t/!\\ Sequence (Lv. "..(dif - 2)..") /!\\\t\t\n\n     "..sq)
        system.sleep(1.5)
        os.execute("cls")
        done = done + 1
    end
    io.write("Sequence: ")
    local answer = io.read()
    if answer:gsub(" ","") == table.concat(sequence) then
        os.execute("color 2")
        print("\nSuccess!")
        summon(dif - 2)
    else
        os.execute("color 4")
        print("\nFail!")
        summon(dif - 3)
    end
end

summon(0)