Here is the full list of all 10 Bus Tycoon ND (Night and Day) achievements.
Your company owns 10 buses!
Your company is in service for 10 days!
Your company owns 5 buses!
You can buy a hydro bus!
You can buy an electic bus!
You can buy new biofuel buses!
You can buy new diesel buses!
Your company is in service for 20 days!
Your company is in service for 50 days!
Your company owns 15 buses!