Am I able to use all free assets in the marketplace in my own product

I wish to make a game and have it published on Steam to help me get into a polytechnic that I don’t meet the entry requirements for, unless I have industry experience. I don’t know if I will or will not make the game free or paid at this point in time.

I have been making a lot of my own assets, but I don’t have time to do most of them. There are a lot of assets in the Starter Content as well as assets in the Marketplace, such as those from Infinity Blade. Am I free to use those in my own game?