Starting from top down:
No power to tax - Congress could not pay for a military or other things to benefit the common good
No power to regulate trade - States might trade unfairly with each other or with other nations.
No executive branch - States felt free to ignore laws the didn't like
No national court system - No one could interpret the laws or settle disputes between the states.
No chief executive - There was no prominent leader to represent the nation and act decisively.
Difficult to amend - It was almost impossible to change the government for the better.
Only one branch of government - There was no separation of powers,, and no checks and balances.