Focus Beam

"The Focus Beam is a mechanical tower that shoots an ever increasing death ray at bloons,".

Its like... in essence, the Inferno Tower from Clash of Clans or Clash Royale. I feel like it deserved some iteration here in Bloons TD, where it would work just as fine.

Stats
Health: 25.

Range: 2/0 Dart Monkey.

Attack Type: A single ray that focuses one bloon until it pops or escapes the range.

Layer Damage: 1... but progressively gets higher every second the longer its focused on a bloon.

Attack Speed: Constant.

Damage Increase Rate: Damage doubles every other second. Once it changes targets, the damage resets.

Pierce: Only attacks one bloon at a time, never re-focusing.

Retarget Time: 1.4 seconds.

Other: Glass Bloons are immune to its attack and can literally just act as an invincible protector of other bloons until it passes.

Cost: $1000.

Upgrades
Still a work in progress. I don't know what to do from here yet...