just to specify: some doors work, i just run over them and get the "exit?" menu... but most doors are broken... especially if numers 25, 30 and 35 are broken
tip: just build foot-soldiers and max catapult for the beginning. get all soldiers moving, as soon as they reach the end, they come back and are useful^^
aim catapult at max range and just wait untill the waves are finished
 "Axon"){kind=icon}
 "Burrito Bison Revenge"){kind=icon}
 "Tower of Greed"){kind=icon}
 "The Great Siege"){kind=icon}
 "Exploit"){kind=icon}
 "W-Zone"){kind=icon}
 "Growth"){kind=icon}