Techno Tower is one of the Stages in Knuckles' Chaotix. As the name implies, the focus of Techno Tower is to get to the top of said tower, primarily by the use of springs.
The stage also features a series of floating platforms which can be used to help reach the top. In Level 5, the player has access to a drilling machine that will drill through five or so walls before breaking. At the end of Level 5, Dr. Robotnik attempts to finish off the heroes.
Upon reaching the top of the tower in Level 5, Robotnik seemingly decides to insult you by placing a glass dome, mini-base on top of it. The player is then brought up via an elevator into the glass dome to battle the dastardly Doctor. In the dome, Robotnik's machine uses ex-tenable arms to try attack the player, as well as using various devices within the mini-base to try outwit our heroes. After the boss is defeated, the Dark Ring powering the machine is released and disintegrates, forcing Robotnik to fly off on his jetpack, causing the player to go back to the World Entrance.