Build & upgrade
Start with 3 hearts, 10 gold and 20 sites. Tap a tower to upgrade or sell for 75%. Extra sites cost 1,000 gold.
Waves & bosses
20 creatures per wave. Call early for more action. Every 10 waves brings a separate boss with 100× the previous wave’s health and half its speed.
Health and speed increases rise every 20 waves. Bosses resist tower effects, but all four support powers work on them.
Stars & gold
Waves 50, 70 and 100 each grant one star, once per map. Wave 50 unlocks the next map. Only the first 100-wave victory saves remaining gold.
Companions
Tap your companion, then a destination. Each kill earns one flower. Contact costs 20 health. A defeated companion revives on the next wave.
Support powers
Bomb: 1,000 damage. Wall: blocks for 5s. Black hole: returns enemies to the entrance for 5s. Blizzard: freezes the entire map for 7s.