3. Space Invaders
What really made people realise that video games were here to stay was the 1978 release of Space Invaders. This Japanese creation featured a horde of aliens arranged in tight formation that descend on you. You control a solitary laser fighter, which can only move laterally.
This was a game of reflexes, as you must destroy all the enemies before they take out all your shields and obliterate you. Apparently, the game was so popular in Japan that for a time, the country ran out of 100-yen coins.