Download Invaders Blitz
Invaders Blitz is an easy variant of the original Space Invaders that you will definitely enjoy. The graphics are retro and they bring in the feeling of the original game, although the enemy ships are now differently colored based on their power and you will be able to read about this in the beginning.
Invaders Blitz allows you to get through a lot of different levels in order to save the planet from aliens. Moreover, if you want your children to play this game, too, you can choose the "easy" option from the menu and they will have a fun time, too.