Flood

This mobile shoot'em up allows players to experience a Flood of biblical proportions. An augmented reality layer of water keeps rising over the course of a few months. Actual player altitude does not matter. The screen displays dangers that need to be faced (read: shot at) solo or in groups. Dangers include madmen, sharks, mutant fishes, giant squids and the odd Deep One.
Groups can be mobile (e.g. car passengers) or immobile (people on a bench). They can take control of large vehicles such as warships and submarines.
At launch, players only have virtual feet in the water, and can use firearms. Later, the scenery changes as water submerges everything, up until the time when only the highest mountaintops emerge from the ocean.