Here is the full list of all 28 Game Dev Studio achievements.
Finish the tutorial
Have a total of 10 employees
Have a total of 20 employees
Have a total of 50 employees
Have a total of 100 employees
Finish 5 contract game projects without any penalties in a single play-through
Finish 15 contract game projects without any penalties in a single play-through
Reach $1,000,000 in funds
Reach $1,000,000,000 in funds
Reach $1,000,000,000,000 in funds
Make a 1/10 game
Make a 10/10 game
Finish the 'Back in the Game' scenario
Finish the 'Pay Debts' scenario
Finish the 'Ravioli and Pepperoni' scenario
Buyout a rival game company
Release your own console
Max out stats on a game engine
Acquire a game engine license
Settle your differences with a rival in a way that doesn't involve going to court
Go to court against a rival game company
Win a court case against a rival game company
Start a slander campaign against a rival game company
With at least 20 employees, have none of them leave to work elsewhere in 5 years in a single play-through
Reach $100,000,000 in funds
Finish any scenario (except for the Tutorial) on Normal difficulty
Set a new standard in any aspect of a game with one of your games
Complete the Console Domination campaign