Assassin's Creed II: Discovery is a 2.5D side-scroller game wherein players assume the role of Ezio Auditore da Firenze. Primarily set in Italy and Spain, Ezio navigates through the game's levels and accomplishes specific goals for each mission. Ezio is able to scale most buildings, as well as roll, jump, and swing through the environment. When encountering enemy guards, the player can choose to either avoid or fight them. Several guard archetypes are present within the game, such as the Halberd Guards (a stationary version of the Seekers), Captain Guards (a more agile variation of the Brute), and Archers. In combat, Ezio can make use of several weapons, including his Hidden Blades, a sword, and throwing knives. Ezio can also silently assassinate guards from different hiding spots, such as ledges, bales of hay, and wooden barrels.
Combat in the game shares many similarities with previous Assassin's Creed titles. When engaging in sword combat, players can execute chain attacks which break the defense of the enemy guards, and also perform counterattacks, which can result in an instant kill or allow for a brief moment to attack. Alongside this, players can perform clash attacks with a target, leading to a test of strength, complete with a pressure bar at the side of the display. Players then have to fight the guard's resistance in order to incapacitate them, or else Ezio will take damage.