add more vehicles possibly military,alien ect...
add enemies that can destroy units and units that specifically fight those enemy's and upgrades for them.
add the ability to click a rock to mine and upgrades for click damage and even the ability to attack enemy's.
general expansion of upgrade trees, possibly different paths that have their own benefits
plz make the enemy's cute mole people
if you're having trouble acing the 13th mission use mages fully upgrade one mage at the beginning then upgrade the others shortly after. continue buying mages and upgrading them fully and you should have no problem holding back the derps.
is anyone else having there guy or whatever do right or left without you touching the keyboard if so message me so i can figure out how to get it fixed
Check out the game pause screen - you can enable the toggle speed there.