How do make a 'This Player entered the game' Gui?

Hey, guys! I was trying to make a player entered Gui that appears and slides down the screen whenever someone joins the game. This is what I tried:

game.Players.PlayerAdded:connect(function(player)
    local msg = Instance.new('ScreenGui', player.PlayerGui)
    local frame = Instance.new('TextLabel', msg)
    frame.BorderSizePixel = 2
    frame.BorderColor3 = Color3.new(0/255,0/255,0/255)
    frame.TextColor3 = Color3.new(0/255,0/255,0/255)
    frame.FontSize = "Size14"
    frame.Font = "ArialBold"
    frame.Position = UDim2.new(0,590,0,-30)
    frame.Size = UDim2.new(0,200,0,30)
    frame.Text = player.Name .. " has joined the game."
    for i = 1,50 do
        frame.Position = frame.Position + UDim2.new(0,0,0,1)
        wait(0.001)
    end
    wait(3)
    for i = 1,50 do
        frame.Position = frame.Position - UDim2.new(0,0,0,1)
        wait(0.001)
    end
    msg:Destroy()
end)

This is inside a regular script, inside the Workspace. It works fine (It does pop up) but it only pops up when YOU enter the game. It doesn't pop up when OTHER PEOPLE join the game. If anyone can help me and explain what I did wrong, I would gladly appreciate it!