The Oil Blue is a self-described "action-sim" that tasks the player with exploring the oceans of the world, reclaiming abandoned oil facilities for their employer, United Oil of Oceania (UOO). The actual game play consists of operating a number of different oil-drilling machines at once, with an emphasis on time management and task optimisation. Some machines, such as the ground well, require very little attention from the player. Others, like the oil derrick, require frequent supervision to prevent pressure levels rising too high and damaging the machine. The player can repair damaged equippment through a series of mini games.
The aim of the game is to produce enough barrels of oil or make enough money to impress UOO so that they will asign the player to a new, larger island. The player earns money by selling the oil they have produced at the Market, the price of which fluctuates over different days.