A 3D update of the 1980 coin-op classic, Defender has players guiding a star fighter from a behind-the-ship perspective in an attempt to thwart an alien invasion. Pilots must once again rescue potential abductees from alien vessels to earn points, which can be used for ship upgrades in the areas of engines, shields, and weapons. The battles take place in a campaign format, playable with a friend in cooperative mode, as pilots engage alien threats across planetary surfaces on Venus, Mars, and Earth, as well as in the far reaches of space.

Six different ships are available to pilot, each offering different characteristics from light and nimble fighters to slow and heavily armed bombers. Techniques such as barrel rolls, loops, and reversals are possible, and familiar weapons such as smart bombs can eradicate multiple threats in one blinding flash. Players navigate the environments with the help of radar denoting enemy fighters in red and friendly units in blue. As a special bonus, the original game of Defender is included as a selectable option.