Tips for stage 3 : 1.spam upgrade income and speed until enemy started first hit on your base,2.spam puncher 20 times then spam upgrade again and repeat all step until max income and speed but when do the step 1,2,if they creat a big army,3.spam many shielder until that army dissapear.4.when money reach 5k summon two bomber and do like step 1,2,3 until they summon boss.5.now only 2 bomber is survive the explosion so spam shield until the army reach the base then stop spam until the bomber active the bomb then spam gun + puncher (if the base survive) then u win ez
A good way to save money is a Gunner spam
Reasons:
Cheap
Doesn't have to worry about getting up close
An army of them can't even let the soda bomber get close
Rarely any can get close
Deploy a single shielder to easily push back a horde of melees