Launch Base Act 1
Twin Hammer is a circular machine with mace balls attached with two little balls. It will follow the player while rotating its maces. It will sometimes take a short break. This gives the player a chance to hit it. However, once the player has jumped, it will try to retreat so it cannot get hit. It should be noted that it is easier to fight as Hyper Sonic or with a Lightning Shield as Sonic because of the ability to double-jump.
The Twin Hammer requires six hits to destroy. Hitting the Twin Hammer three times will destroy one of its maces, thus making the next three hits easier to score.
As Knuckles in Sonic the Hedgehog 3 & Knuckles, instead of entering the building that comes before this fight, he scales the wall to find a hole in a higher wall leading to what would appear to be an unused part of the base. He finds himself in a pit with not one, but two Twin Hammers, making it more difficult to proceed. Knuckles' reduced jump height does not help either, as he must wait until the robots are very low before he can even score a hit. Once they are both destroyed, the floor crumbles away and Knuckles drops to a lower level where the Goal Plate appears.