Flow Field Defense

Every maze tower defense is a game about shaping a cost field, and none of them show you the field. This one draws it under the board. Build a tower and watch the whole landscape of walking times tilt, then watch the enemies follow the new gradient downhill.

• A tower is not a wall but a cell with a finite traversal cost, so walling the goal in completely is a legitimate and expensive move rather than a forbidden one. The pathfinder decides whether going around or chewing through is cheaper, and you can see where it changes its mind.
• Five enemy types are five parameter sets of one cost function: how much a second of walking is worth against a point of health, and how sharply the choice is made.
• Hovering a build site prints the honest numbers. A longer detour through empty ground buys you nothing, and the readout says so.
• The cost-to-go field is the first arrival time of a wave through the same medium, which makes this the same equation as the ripple tank.