|Game||Sin & Punishment: Star Successor|
|Stage #||Stage 3|
- "Infiltrating the Sky Fortress requires a unique perspective on shooter gameplay. A side-scrolling romp through the fortress halls leads right into the inner sanctum, but enemies in the background require constant attention along the way. Quick shooting and savvy swordplay will be essential."
- — Sin & Punishment official website
Sky Fortress is the second major stage in Sin & Punishment: Star Successor.
After escaping the Undersea Tunnel and defeating Armon Ritter, Isa and Kachi head to the Sky Fortress. After fighting their way to the building's inner sanctum, they are stopped by another member of the Nebulox, a strange girl named Hibaru Yaju. They fight her and win, but are attacked by the Horror Keeper before they can accomplish their goal. Following a long struggle against the duo, the Horror Keeper is defeated, but it badly damages the fortress in the throes of its death. Kachi teleports herself and Isa away before they can be hurt by falling debris.
The first half of the stage is a side-scrolling section, as opposed to the usual perspective. The player must fight off enemies in both the background and the foreground. Swarms of enemies appear in the background(though most of these are not aggressive) and stronger enemies in the foreground, many of whom use melee attacks. Guardian 11 is fought in this area. After it is defeated, there is a section in which the player is sandwiched between jets of flame and large machines armed with circular saws. The machines may be destroyed, but the jets are indestructible. In order to get past the jets, the player may dodge past them, or large machines in the foreground and background may be used to block them.
The second half of the stage returns to the usual perspective. This section winds through the inner halls of the fortress. Throughout this area, the player is assaulted by more enemies, some of which will break through the walls surrounding the player's character. As such, the player must be on his/her guard at all times. Later in this section, the player will be blocked off by destructible walls barring his/her path. These walls are composed of many yellow blocks, plus a larger red block. Each yellow block can be destroyed with one shot, but shooting the red block will destroy them all. At the end of this section, the player must fight Guardian 17, Hibaru Yaju, and the Horror Keeper.
Strangely, aside from the Horror Keeper and Hibaru Yaju, none of the enemies or bosses in this stage have any clear connection to the Nebulox or the Keepers.