There are three easy achievements you can unlock in about one minute in Game Dev Tycoon. These achievements are:
Fan - Pick an inspired company name
Treasure Hunter - Activate the hidden treasure in the garage
And
Detective - Find at least one of the easter eggs in the game (which is accomplished at the same time as Treasure Hunter
As soon as you start the game, name your company, “Valve”. You can name it one of a handful of famous real world game studios as well, but I don’t have a list of what works and what doesn’t. Valve does work though.
Next, you just need to create a game called “Pong”. I don’t think anything else with the game’s development matters, as long as you name it Pong.
During the development you will see the pong poster in the garage become animated, and this is the garage’s hidden treasure, and also counts as the easter egg for the detective achievement.