Besides main required functional includes, you may need other includes, like themes and plugins. Those reside in /themes/ and /plugins/ sub-directories respectively.
I.e.:
<script src="https://www.amcharts.com/lib/3/amcharts.js"></script>
<script src="https://www.amcharts.com/lib/3/serial.js"></script>
<script src="https://www.amcharts.com/lib/3/themes/light.js"></script>
<script src="https://www.amcharts.com/lib/3/plugins/dataloader/dataloader.min.js"></script>