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.
Completed all levels
Forty maps solved
OHH! Fifteen maps completed using less objects than planned
Finished ten maps using less objects than the plan
Thirty maps solved
Uou! Solved fifteen maps in less than one minute.
Solved twenty maps
Finished 10 maps in the first try
Completed five maps using less objects than planned
Solved ten maps with less than one minute
Solved ten maps
Solved five maps with less than one minute
Completed two maps using one single object.