Welcome to the Tangled Woods! This stage is part of the second world. It is a tad more complex than earlier stages, and will test your strategic awareness in several fields at once. The level has two spawning UFOs and a tangled path. Strong attacking towers, such as the Power Tower will prove extra useful. Tangled Woods also introduces the Frost Tower, which is used to slow down enemies for optimized attacks.
A good tip is to destroy blue crystals for extra gems whenever you can – it will make the level a lot easier to overcome. Building a ranged tower (the Scout) in the center will make most of the crystals reachable, and also provide for a good defense.
Pay attention to the timeline, so you know exactly when the Flying Drones are coming. You may only counter them by building Anti-Air Cannons.