THE INSECTS ARE COMING

The alien insect swarm has begun its attack. Place your towers wisely — the ground you hold is the only thing between them and the base.

You will fall. That is part of it: every run leaves you with knowledge and with upgrades that carry over, so come back stronger and go further than the last time.

Boulders lie scattered across the pit. They block the insects and your building alike, and only a Collector at level 2 can clear them — which is one way to open a lane where there was none.