Gameplay involves the player being able to interact with the environment, and the realistic water dynamics. Rob Hewson stated that "player versus environment is certainly a large part of the experience, the wonderful thing about water is that it is constantly affecting every area of the environment, so you get incredible amounts of emergent behaviour. The player constantly has to adapt to the environment and react quickly because doors, walls and windows are going to cave in differently each time according to the distribution of water.
Players can visit previous locations that have been submerged and are able to interact with them in various ways. Hewson stated that players are able to "fight through an area one time and there might be a foot of water flowing around and affecting the environment, another person might play through the same area and blow out walls or windows causing a great deal of water to flow into the scene, meaning perhaps the gameplay switches to floating cover. Another player might shoot fuel barrels which let even more water into the scene but also spawn floating fuel fires which are carried around with the flow and find they need to resort to underwater action.
This article uses material from the Wikipedia article Hydrophobia , https://en.wikipedia.org/wiki/Hydrophobia_(video_game) which is released under the Creative Commons Attribution-Share-Alike License 3.0, https://creativecommons.org/licenses/by-sa/3.0/.