Nowhere does it say that you must purchase a license in order to complete the platform tutorial
synbios128: It is not the case.
The only thing is that you don't have the graphical assets provided to you. But the logic of use of the software still applies and is complete.
Do a search on google or in the "tools/resources" part of this forums and you will easily find graphical assets you can use instead.
Also there are a lot of tutorials you can check.
You can also check those video tutorials I made with which graphical assets are provided too.