Here is the full list of all 16 Universe Sandbox achievements. It takes around 200 hours to unlock all of the achievements on Windows.
Start Universe Sandbox 10^4 = 10000 times
Rule over your universe for 12 months
Rule over your universe for 30.4 days
Start Universe Sandbox 10^3 = 1000 times
Rule over your universe for 24 hours
Start Universe Sandbox 10^2 = 100 times
Start Universe Sandbox 10^1 = 10 times
Result of millions of years of computation
Some will know from their childhood; some were not born yet
Finish five tutorials
Rule over your universe for 60 minutes
Crash the Earth into the Sun
Freeze the Earth by moving it farther from the Sun
Capture 100 screenshots
Rule over your universe for 60 seconds
Start Universe Sandbox at least once