Ability to use Include Package Assests within Unity Commercially?

You can use any assets that Unity gives you, but you cannot take a Unity demo and claim it is yours. Also, you can sell anything for free until you make $50k a year, then you have to buy the pro license. That is all I know but you can also check out the Unity terms and conditions (like anybody reads that) and you can find out more. Good luck!

@MrProfessorTroll

Thank you for that answer. And when you say 50k a YEAR, does that mean when I make 50k every year, or make a total of 50k from the game? (I really doubt I would even make 1k, to be honest..)

Thank you again, and thanks if you answer that question.

It's not $50K, it's $100K, and it's in the previous fiscal year.