Heat Mode

Heat Mode is a game mode unlocked at Level 42. This mode is similar to the Normal difficulty, except the map look like it's on fire. Not other than that, all bloons are on fire when entering the map. All towers will catch on fire immediately when placed, and dies 60 seconds after you place them down. The longer a tower has been burning, the less you get back when you sell it. No bloon is immune to the fire except blimps. Completing 65 rounds on this mode rewards you with 200MM, due to it being harder than hard difficulty.