Discovery takes place after Assassin's Creed II and before Assassin's Creed: Brotherhood. The player assumes the role of Ezio Auditore da Firenze and mostly takes place in Spain where Ezio is fighting inquisition while trying to free his fellow assassins and foil the evil schemes the Templars are plotting.
The game uses full 3D graphic but with a fixed camera so it runs and feel like a side-scrolling platformer. Ezio is as deadly as ever, but his arsenal is limited to his blade and throwing knives. Each mission has a certain mode that somewhat decides how the level should be played. Stealth mode lets you get spotted by the enemy only a certain number of times before you have to restart from the last checkpoint. Chase mode requires you to run away or reach some place or someone within the time limit. And normal mode lets you choose the mission approach you wish to use. You can run and slash at the enemies or sneak and use stealth kills.
Unlike console versions of the games, leap of faith is fairly limited and you will never see the hay you are leaping into, and most will happen as a cut-scene anyhow. But there are hiding places such as shadows, hay carts, bushes or empty barrels that will help you in your sneaking missions. If you approach the enemy from behind you can perform a stealth kill with a single strike, but if you prefer the frontal assault the type of fight will vary based on your opponent. Stronger opponents can block your attacks and you have to either break their defense or rely on counter-attacks to harm them. All moves will not be available right from the start and will gradually open as the story progresses.