High Energy Beacon was released on Mar 22, 2012, being the current final upgrade for the path 1 upgrades for Monkey Village, replacing Energy Beacon. It costs $10,200 on Easy, $12,000 on Medium, $12,960 on Hard and $14400 on Impoppable. All towers within its range with Special Abillities have their cooldowns reduced by 20% (50% on BTD5 iOS) and the village itself gets a powerful energy beam attack. This beam doesn't stop and the locked Bloon loses all its layers very quickly. This upgrade also increases the range of the Monkey Village.
The laser generator appears to be inside a robotic eye that will even look around and blink.
Possibly a reference to the Eye of Sauron, which is a giant eye on top of high tower in the middle of a large fortress from The Lord of the Rings trilogy. In addition, the eye of the High Energy Beacon Village is constantly blinking and moving around erratically in a similar fashion.
Homage to HAL 9000 from the Space Odyssey.
In the Mobile version, the eye appears to be hyper-realistic and the beam is also purple.
Also, the upgrade name was shortened to Energy Beacon due to the size of the upgrade button.