Round 37

Round 37 is a round first introduced in Bloons TD 4. It is characterized by various spaced rushes of different types of Thermal Bloons (i.e. Black, White and Zebra Bloons) together with Lead Bloons. Since Bloons TD 5, the round also ends with a Camo White Bloon rush.

Description
The round starts with a stream of Black Bloons. After spawning the Black Bloons, White Bloons appear right after, without interruption. Right after the last of those White Bloons spawn, Lead Bloons spawn, but as Leads are much slower, it may appear to be a break between the Whites and Leads. After the leads spawn, Zebra Bloons spawn immediately. Finally, after a five-second break, 7 Camo White Bloons spawn.

Strategy
This is a test of a defense's ability to handle Thermal Bloons. Defenses relying on Ice Monkeys, Bomb Shooters, Bomber Aces or Mortar Monkeys will have to watch out, as all the bloons in this round are immune to at least one of them. The player will also want to brush up on their Camo Detection, due to the camo whites at the end of the round.

Tips

 * Striker Jones will allow all explosions to have a 50% chance of popping Black and Zebra Bloons when upgraded to at least level 5.
 * Towers with other Damage Types than Explosion or Cold, such as the very common Sharp , should have little trouble beating the Thermal Bloons.
 * Two Glue Gunners with Corrosive Glue greatly weaken every single non-camo Bloon this round. With Stickier Glue, they can even beat those bloons alone on long maps.
 * A Spike Factory at the end of the track stands a good chance of handling the camo whites, since the round is very long, taking almost 40 seconds to spawn the camos.