Crucible of Fire

In this Expert track, bloons come from only one side, but the fire can spawn more bloons. Towers can be placed on the light gray part where the fire forms, but they might get set on fire, doing 5 damage per second! Fire switches every few rounds. Bloons are sometimes spawned from the opposite side.

Red Fire
Rounds 1-15: Red Bloons

Rounds 16-21: Pink Bloons

Rounds 22-29: Black Bloons

Rounds 30-37: Lead Bloons

Rounds 38-59: Rainbow Bloons

Rounds 60-64: Basalt Bloons

Rounds 65-70: BLAZE

Rounds 71-96: BFB

Rounds 97-130: MAGMA

Rounds 131+: IGNIS

Yellow Fire
Rounds 1-13: Red Bloons

Rounds 14-18: Yellow Bloons

Rounds 19-32: Pink Bloons

Rounds 33-62: Rainbow Bloons

Rounds 63-71: BLAZE

Rounds 72-97: BFB

Rounds 98-135: MAGMA

Rounds 136+: IGNIS

White Fire
Rounds 1-12: Red Bloons

Rounds 13-17: Pink Bloons

Rounds 18-24: White Bloons

Rounds 25-30: Zebra Bloons

Rounds 31-51: Rainbow Bloons

Rounds 52-67: MOAB

Rounds 68-85: Astral Cruiser

Rounds 86-93: GLOW

Rounds 94-119: MAGMA

Rounds 120+: IGNIS

Blue Fire
Rounds 1-14: Blue Bloons

Rounds 15-26: Black Bloons

Rounds 27-36: Lead Bloons

Rounds 37-43: Ceramic Bloons

Rounds 44-67: MOAB

Rounds 68-82: Astral Cruiser

Rounds 83-89: GLOW

Rounds 90-110: MAGMA

Rounds 111+: IGNIS