To this day, Space Invaders is one of my all-time favourite games. Born the same year as me (1978), it is a classic in every sense of the word.
What I love is the simplicity, There is no heavy backstory, there is no complicated power-up system, no fancy boss battles or in-game purchases!
The instructions whole scene was set in one line of the four lines of instructions.
Game ends when players “Laser Bases” are all hit by invaders missiles or when invaders overun the base.
Simple as that! In one line of text, you know everything you been to know. You control a laser base and you need to defend it from the invaders. You quickly learn that there are some building you can hide under, but they can be destroyed and that from time to time a bonus can be had from hitting the mothership style alien.