The issue is not that you can't do that anymore; it's that the things you (and presumably, your friend) want to do have gotten more complex. That's just a fact

The issue is not that you can't do that anymore; it's that the things you (and presumably, your friend) want to do have gotten more complex. That's just a fact of life. It's going to take a lot more effort to write Wolfenstein: The New Order than Wolfenstein 3D.