Medal of Honor: Frontline

Grenades are very useful on Hard difficulty when you know where the enemy is going to come from and I also use them alot whenever I'm about to enter a room. If it lands on a enemy directly it immediately explodes. Also remember to turn on 'cook grenades' in Options menu to allow you to cook them and throw for immediate impact. Level 14 is a good spot as enemies in the train cars have no where to run and are bunched together. Previous kills add to the total even if you die and restart.