missle radar system

[acoustic gate]

try this

if misslesON then
    local x = Instance.new("ScreenGui")
    x.Parent = game.StarterGui
    local y = Instance.new("Frame")
    y.Parent = x

    game:GetService("RunService").RenderStepped:Connect(function()
        for i, v in pairs(workspace:GetChildren()) do
            if v:FindFirstChildOfClass("Humanoid") and v:IsA("Model") then
                local character_frame = v:GetPivot().Position
                local view_position = Camera:WorldToViewportPoint(character_frame)
                y.Position = UDim2.new(0,view_position.X,0,view_position.Y)
            end
        end
    end)
end

Creating so many frames

In a loop

Will impact performance

A lot