Yap, the demo is missing the atmosphere, the scenarios, and the complete gunplay. At least you can upgrade the weapons.
e.g., In Chapter 7, you face more powerful enemies trying to overwhelming you. In these demo chapters, it's more about the player feeling out the world. So the experience will be different. If your friend bought it cheap later, you might want to give R3 a try again to see if you dig it. If you still don't feel anything after Chapter 7, then it's time to move away from the game. ^_^
e.g., In Chapter 7, you face more powerful enemies trying to overwhelming you. In these demo chapters, it's more about the player feeling out the world. So the experience will be different. If your friend bought it cheap later, you might want to give R3 a try again to see if you dig it. If you still don't feel anything after Chapter 7, then it's time to move away from the game. ^_^