Quick Answer
How progression is structured
Each major location works like a survival-horror maze. Players find keys, solve environmental locks, reopen shortcuts, revisit red rooms that still contain items, and return to Safe Rooms before moving toward the next chapter area.
Flooded streets and boats create an impression of a wider Arkham, but the campaign controls which route is currently available. Earlier areas are not presented as one permanently open city map.
Why some descriptions say semi-open
The individual hubs can be broad and allow optional investigations or alternate short routes, which leads some outlets to use the term semi-open. That describes local freedom inside a chapter, not a conventional open world with unrestricted district travel.
Players who liked the first game's detective sandbox should expect a substantial change. Players who prefer Resident Evil-style maps may find the tighter structure easier to read and more effective for horror pacing.
Sources
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