ZAP! is a compilation of eight single player space shooters in the fixed screen genre. The games have all been previously released by Alawar Entertainment, Inc . The games in this compilation are: Alien Outbreak 2: Invasion Back to Earth Back to Earth 2 Crusaders of Space Crusaders of Space 2 Crusaders of Space: Open Range El Airplane Pulsarius The following game is not in the same genre and is included as a bonus game Cubozoid