Here is the full list of all 13 Bad Rats: the Rats' Revenge achievements. It takes around 5-6 hours to unlock all of the achievements on Windows.
Forty maps solved
Completed all levels
Thirty maps solved
OHH! Fifteen maps completed using less objects than planned
Solved twenty maps
Finished ten maps using less objects than the plan
Completed five maps using less objects than planned
Completed two maps using one single object.
Uou! Solved fifteen maps in less than one minute.
Solved ten maps with less than one minute
Finished 10 maps in the first try
Solved ten maps
Solved five maps with less than one minute