Still more impressively is that no matter where you are the entire view is rendered in realtime just like an open world game. Makes the visuals and game engine even more impressive.

Looks good hopefully it will add replay value to discover all those areas.

Ditto. Miss my new best girl though. Losing her must have been traumatic for poor Al. Like Tom Hanks losing Carey Lowell in 'Sleepless'. From what I remember. Not that I watch it a lot or anything.

would be good if it was a sandbox game, its gonna be stage by stage instead

It looks like free roaming is more feasible in RPGs, where you can de facto lock areas the player isn't supposed to reach immediately making the access almost impossible before reaching a certain level, after that the player can roam freely. Indoor, underground and other well separated or isolated areas, though, could be simply blocked with doors, gates, drawbridges, etc until the player gets a key or whatever, also in other genres.

Morrowind and Gothic are almost totally free roaming, for example, nevertheless it's very difficult to visit some areas too early without being killed very fast, and the quest and subquest systems generally manages quite well actions and dialogs to avoid messing future quests up unless the player voluntarily do it, for example attacking and killing not hostile NPCs.