Nexus Defense has 4 levels with the number of spaceships to destroy increasing with level. There will be 1 plane on your field, enemy spaceships will move from the bottom of the screen up, the plane will automatically shoot the spaceships, destroying the spaceship has a chance to receive 1 crystal, accumulate crystals to buy items to help freeze all enemies, explode all enemies or pick up all crystals quickly. The number and flight speed of the spaceships will increase. Use 20 crystals to summon more planes when there are enough 6 planes, click buy more to upgrade a random plane to the next level with greater power, each plane has 5 levels to upgrade. Destroying enough enemy spaceships will win, on the contrary, letting enemy spaceships fly past the screen will reduce blood until all blood is gone and you lose. See the types of plane multiplication on the Defenses screen.