If you don't do anything than traditional copyright controls and sales law will apply.
Most games do operate on a license agreement. I've never heard of Hotline Miami, but when I look at it on gog it includes EULA.text. I assume that similar fine print exists in the other titles as well.
Under traditional sales doctrine the seller has a number legal requirements, such as that the product be reasonably free of defects, that it is fit for the purpose it was designed for, that it is not unreasonably dangerous, and so on.
Imagine: If the game crashes one it could be grounds for lawsuit. If the game harms your computer it could be grounds for a lawsuit. If the game does not satisfy the statements in the ads about it being fun, it could be grounds for a lawsuit. The lawsuits are unlikely, but you don't want to pay for even a single one of them.
A license agreement moves it away from traditional sale law and moves it into a contract.
Most license agreements disclaim all implied warranties such as fitness and merchantability, and do their best to limit the damage a potential disgruntled customer could cause.
Before you release your game you really should talk to a business lawyer to make sure you have done all you need to do. The $150-$300 up front in legal costs can be far less than the many thousands of dollars (or even hundreds of thousands of dollars) for making a serious business error.