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  • Devin Becker thinks this is interesting:

Dungeon Keeper, another hybrid, makes a particularly interesting example because construction is actually excavation; it takes place underground, and the player can’t see the area he is digging into. Excavations often encounter immovable rock or lead to previously unknown caves, underground rivers, or pools of lava. Excavation is also irreversible; the game offers no way to close an excavated area. This encourages players to be cautious. Suddenly digging an opening into an area full of enemy creatures is a major hazard of the game.

From

Cover of Fundamentals of Construction and Simulation Game Design

Note

Some F2P games (including the Dungeon Keeper one) use expansion as an important component of growth.