The Grapple Lasso appears in Metroid Prime 3: Corruption, and is one of the first upgrades in the game. The Grapple Lasso is a variation of the Grapple Beam, that will allow Samus to grapple certain enemies and items. After locking onto a Grapple Point, thrusting the Nunchuk forward will cause Samus to attach her Grapple Beam to the obstruction. She can then rip it away, which is accomplished by yanking the Nunchuk back. In addition, by twisting the Nunchuk in various directions Samus will imitate the motion, adding to the immersion of the game.
Most often, the Grapple Lasso is used to remove obstacles, such as damaged panels. However, the Grapple Lasso also has offensive uses as well:
"Dragoon" Battle Drones use special jets to stay in the air; the Grapple Lasso can be used to tear the jets off, causing the Drone to crash.
Phaz-Ings and Adult Gragnols can be killed using the Grapple Lasso. Pulling them with the Lasso produces enough physical stress to kill them.
Several Boss fights (Aurora Unit 313, the Korakk Beast, and the Defense Drone as examples) have some mechanic that requires the Grapple Lasso, most often in the form of a protective covering that must be removed in order to access the Boss's weak point.
Every variety of Pirate Aerotrooper (regular, Armored, Advanced, and Assault) can have their jetpacks torn off. However, to do this the Aerotrooper must first be ignited (which requires the Plasma Beam or Nova Beam), and Armored/Advanced/Assault Aerotroopers must have their armor removed before they can be ignited.
The reflective energy shields carried by some Space Pirates can be pulled out of their hands, greatly reducing their defenses.
Later in the game, Samus gets the Grapple Voltage which lets Samus use the Grapple Lasso the absorb energy or inject it into targets.