Here is the full list of all 29 Startup Company achievements.
Have an employee reaching a base speed of 480%
Fire 10 employees
Research everything
Invest 100% of Space-based Solar Power
Invest 100% of Tidal Power Plant
Play for more than 1000 in-game days
Choose a not so creative website name
Take out 1 loan
Become #1 Social Media product
Resolve 1000 support tickets
Secure a retirement fund of more than $200,000,000
Secure a retirement fund of more than $45,000,000
Invest 100% of Fusion Power Plant
Secure a retirement fund of more than $1,000,000
Secure a retirement fund of more than $500,000
Own less than 10% of your own product
Fire 5 employees
Have a monthly profit of at least $0
Fire 1 employee
Hire 10 employees
Hire 5 employees
Hired 1 employee
Produce 1 million CU with all servers at 200%
Reach an inventory of more than 100,000 of the same component/module
Go bankrupt
Became Top #1 of all website types in one game
Reach 1,000,000 users while still in the smallest office building
Reach an average response time lower than 2 hours with more than 500 tickets
Secure a retirement fund of more than $3,500,000,000