Bigger Bombs

Bigger Bombs is the first upgrade to the Bomb Tower in Bloons Tower Defense 4 and the first upgrade of path 2 in Bloons Tower Defense 5. As it says in the description, bigger bombs affect a larger area, popping more bloons. It can be effective with any kinds of rounds. Useful for popping large groups of bloons. This is why this upgrade should be bought in the early rounds.

Costs
In BTD4 and BTD5, it costs $340 on Easy, $400 on Medium and $430 on Hard

Appearance
Bigger Bombs looks very similar to the regular bomb tower. All that changes is the appearance of a target on the back of the Bomb Tower. After all, all that really changes is how big the explosion is.

Trivia

 * Bigger Bombs doesn't increase the speed.
 * BTD5 is the only game that the icon for Bigger Bombs is not a Pyrocumulus Cloud
 * In BTD5, bombs fired by a Bigger Bombs Tower are red.