From back of the game box:
As the Commander-in-Chief of the invasion forces, the player is presented with a vast choice of actions and possibilities. Based on WWII, but not on a specific event, Invasion Force is not limited by historical facts, unit types or strengths. The player has FULL command from the receipt of the coded message to invade, capture or destroy. Choose from a large scale infantry attack, a small elite group of commandos, fly in paratroops or send in the tanks and artillery.
Game features include, demonstration games, 3 levels of difficulty, save game facility, large, fast scrolling map, and a smaller tactical map for easy position location, hidden or visible movement, land sea and air battles, demolition and air-landed units, transport for artillery and infantry, easy icon selection, 1 or 2 player option. Joystick recommended.