Raise an army of baddies and fight your way back into the dark forest.
The enemies will try to take the kids from your camp and take them away. Don't let this happen ! Build and upgrade towers to attack them. Building / upgrading towers costs gold. You earn gold by killing enemies. Using spells costs mana. Mana regenerates with time.
[P] - pause HOLD [SHIFT] to build several towers of the same kind HOLD [SHIFT] to keep a tower selected after upgrading  - select / unselect firebolt  - select / unselect chain lightning  - select / unselect zombies