User blog comment:GameboyGabriel/What new things will there be in BTD6?/@comment-1676226-20130529084142

Maybe Archer Monkey? I don't know what the prices would be...

Basic tower - Can pop 1 bloon per arrow. - Can pop 1 layer per arrow. - Fires 1 arrow per second. Path 1 U1- Can now pop up to 3 bloons per arrow.
 * U2- Can now pierce through 3 layers of a bloon per arrow.
 * U3- Can now pop up to 10 bloons per arrow.
 * U4- Can now pierce through 5 layers of a bloon and can stun MOAB- class bloons by 2.5 seconds per arrow. Does not affect ZOMGs.

Path 2 U1- Can now fire up to 2 arrows per second.
 * U2- Can now fire up to 3 arrows per second.
 * U3- Can now fire up to 5 arrows per second.
 * U4- Activated Ability: Can fire up to 10 arrows per second. Lasts 10 seconds. Cooldown is 25 seconds.

It's very simplistic. :)