After finishing a level when clicking "Next Level" please ensure that the Mode is kept for the next level instead of falling back to the Easy Mode again.
Would be much easier then selecting the Path, Level Map and Mode all over again after each level.
Thanks a lot for the game. Love it.
Apocalypse mode is not hard enough, the final boss is funny, but not match with 4.000 M Pop and 25k free money.
Just use bunkers and upgrade them at the right time.