Nintendo has confirmed that Splatoon will be releasing on May 29, 2015. During the Nintendo Direct, several modes were showcased including Ranked Battles and the Battle Dojo. Ranked Battles feature a ranking system (naturally) and would be similar to Super Smash Bros.’ “For Glory” mode. The Battle Dojo is a new mode that allows 2 players, one using the Wii U GamePad and one using the TV, to hone their skills. There are balloons throughout the levels so it’s mostly a target practice mode where players can develop skills and strategies.
Splatoon amiibo are also coming soon. Nintendo confirmed a boy inkling, a girl inkling, and a squid amiibo. Players can choose to pick up all 3 in a set or purchase the boy or girl inkling separately. The amiibo can also unlock special missions and unlock various outfits in the game.
Source: Nintendo Direct