From Sonic Retro
|Sixth level, Sonic Forces|
|Level themes: industrial, desert/western|
|Played as: Modern Sonic + Avatar|
| Non-English names:|
|← Egg Gate | Luminous Forest →|
Arsenal Pyramid is the sixth stage of Sonic Forces, and the introductory stage for the Tag Team gameplay style where the player controls Modern Sonic and the Avatar simultaneously. It is also the second stage that is located in Green Hill Zone from Sonic the Hedgehog, but with a new setting inside a huge pyramid that serves as a weapons arsenal and loads for the Eggman Empire.
Prior to the events of the game, Dr. Eggman worked inside the Arsenal Pyramid, eventually discovering the Phantom Ruby right at his doorstep. While studying this mysterious gem, the Jackal Squad show up to raid his base. When the squad's leader strikes the Ruby and his vision of an ideal world, a desolated land, shown before him and Eggman, the doctor convinces him to join his cause. Later on, E-123 Omega infiltrated the base as part of a reconnaissance mission, only to conduct wanton slaughter of several Eggman robots much to Rouge's chagrin. This would attract unwanted attention from Infinite, leading to the E-Series robot's defeat. Shadow then arrives to investigate Omega's last whereabouts.
Much later, Sonic and the Avatar arrive under orders from the Resistance to attack the pyramid-shaped factory. Knuckles suggests sending reinforcements, but Sonic replies he and the Avatar can handle it. With directions from Amy, Sonic and the Avatar infiltrate the factory and fight the robots, eventually reaching their goal.
As an introduction to the Tag Team style, the player controls both characters at the same time, with the lead character switching to Sonic when Boosting and to the Avatar when using the Wispon. To accommodate the different characters, the stage has mechanics for both of them, with capsules containing White Wisps for Sonic to charge the Boost Gauge with, and floating targets for the Avatar to use their grappling hook on.
The stage begins with a linear road leading up to the pyramid itself. After passing the Checkpoint, the player is prompted to activate the Double Boost, which will allow Sonic and the Avatar to boost through enemies and break into the pyramid. Inside the pyramid, the player has to skydive through laser grids, then cross a myriad of giant gears that serve as platforms, taking out waves of Egg Pawns that impede progress. If the player brings a Lightning Wispon into this stage, then they can use its special action to travel along paths of rings and take large shortcuts through the pyramid interiors, thus making the Lightning Wispon ideal for this stage.