I've played Game Dev Story for iPhone for quite a while now, and winning a GGA Grand Prize seems to be quite difficult. So far, I've only won one, despite high (36+) review scores on many games.
The one time I won the Grand Prize, I released 4 Hall of Fame level games that year, and ended up winning Best Design, Best Sound, Runner Up, and Grand Prize. Is this the only way to win the Grand Prize?