Simplify the following text for a Grade 8 native English-speaking person.
Original: Super Space Invaders ' 91 , Space Invaders DX and Space Invaders 95 were included in Taito Legends 2 , a sequel compilation released in 2006 .
Simplified: The game is about protecting the Earth from the Space Invaders by controlling by shooting them all before they can land . There have been seven versions of Space Invaders made by the Taito Corporation .