It's because Heavy Rain IS NOT A GAME. It certainly isn't a movie, but it's more movie then game. There's no in-game goals, there's no penalty, you can't lose. Heavy Rain is NOT a game. MGS4 is a game, just not a very good one. It's not a great movie either. Mass Effect on the other hand, has clearly defined goals, clearly defined penalties, and a "game over" scene. Also, while you may argue that since Heavy Rain isn't a game, the dialouge sections of ME are not games either. However, there often is a goal to them, and a reward/penalty.
Simply put, people say that Heavy Rain is a movie because it's more movie than game. MGS4 just has hour-long (crappy) cut-scenes.







