Fireball
Tap to launch from the fortress at the closest enemy, exploding on impact (scales with wave)
Spells
Unlocked once with gold, then castable for free on a cooldown. Two of the three scale their damage with the wave number, so they stay relevant late.
The three spells
Chain Lightning
Tap to strike the densest enemy cluster from above and arc between them (scales with wave)
Freeze Burst
Tap to freeze every enemy on the map for 1.2 seconds
| Spell | Unlock | Cooldown |
|---|---|---|
| 🔥 Fireball | 10g | 15s |
| ⚡ Chain Lightning | 10g | 15s |
| 🧊 Freeze Burst | 12g | 15s |
When to cast
Cooldowns are identical at 15s, so the real question is what each one solves. 🔥 Fireball is single-point burst against whatever is closest to breaking through. ⚡ Chain Lightning looks for density, which makes it the answer to a wave of runners or post-split splitters. 🧊 Freeze Burst buys time rather than dealing damage — it is the panic button when a leak is already happening, and the cheapest way to survive a boss whose shield is up.
Campaign levels grant spells individually; check each level page for which are available.