Jaws is an NES game released in 1987 by publisher LJN; it is based on the movie franchise of the same name. The game itself is more akin to the fourth and final Jaws, Jaws: The Revenge, than the other three films. Jaws features top-down, side-view, and first-person gameplay.
The game starts out in top-down view at the port located on the left side of the game map. The goal is to navigate the boat across an open sea to reach the ports at opposite ends. By doing this the player acquires (in exchange for conch shells) a device useful for tracking Jaws, as well as gain increased attack power for attacking Jaws itself. While in the open sea, the boat will randomly "hit" things. The game will switch from a top-down view (as the boat) to a side-view (as the boat or the diver). If the boat runs into small sea creatures and not Jaws, the boat will immediately release a diver into the water in which the player then controls. If Jaws hits the boat instead, it will temporarily be possible to attack Jaws with the boat's depth charges. Once Jaws physically hits the boat in side-view, the boat disappears and the diver is released. It's also possible to fight Jaws in the side-view mode if it happens to be nearby when the boat hits something else (eventually showing up on the scene). It's worth mentioning that Jaws (for some reason) cannot harm the diver while he's at the very top of the screen. This is good to remember when Jaws is around.
Denizens of the Deep
Once in side-scrolling view, the diver will have to face dangerous sea life including: sting rays, jelly fish, smaller sharks, and sometimes Jaws. When killed creatures will drop one of three different items the diver can collect: crabs (speed up the diver), starfish (points), and conch shells (a form of currency in the game). One can speculate that the smaller sharks are perhaps Jaws' own offspring, as they often accompany Jaws while attacking. Once enough of the smaller sharks have been killed, a mini "bonus game" will be initiated. The player will then be switched to a side-view flying a plane over the ocean. The goal is to bomb jellyfish as they move around in varying patterns below. The plane can be sped up or slowed down by simply holding down left or right on the D-pad (depending which direction the plane is flying). After the last wave of jellyfish the player is rewarded conch shells based on how many they hit and the bonus game ends.
We all live in a...orange submarine?
At some point in the game (usually after the two ports have been visited enough times and powered up) a submarine will appear somewhere on the game map. Navigate the boat over to it, and the sub can be used. Once acquired, the boat will release the submarine into the water instead of the diver. The submarine has two different attacks (torpedoes and depth charges), and moves much easier through the water compared to the diver. The drawback is that the "top of the screen" trick no longer works. If either Jaws or another creature hits the sub, the diver releases from it and it can no longer be used. In some cases it is possible to reacquire the submarine after it has been lost. Regaining power levels after losing a life, for example, could cause the submarine to reappear on the game map.
The Final Fight
Once the ports have been visited enough times and the attack rating has been sufficiently powered up, the player will then be able to inflict enough damage on Jaws in side-view. Bringing Jaws' power bar all the way down will initiate the final confrontation with Jaws. This fight takes place in first-person perspective with the player controlling the front of the boat. The objective here is to force Jaws to jump out the water (using the A Button), and then ramming it with the front of the boat (using the B Button). Jaws needs to be lined up perfectly with the boat, and the right distance away, for this to work. It can be tricky, but with practice it's easy to learn where Jaws needs to be. Once Jaws has been impaled with the front of the boat the game cuts to the ending and credits.