Sonic Forces is a platform game developed by Sonic Team and published by Sega. Produced in commemoration of the Sonic the Hedgehog franchise's 25th anniversary, it was released for Microsoft Windows, Nintendo Switch, PlayStation 4, and Xbox One in November 2017.
The game was primarily developed by staff who had worked on Sonic Colors and Sonic Generations, using an updated version of the Hedgehog Engine, used in Sonic Unleashed and Generations. Development began after the release of Sonic Lost World in 2013. The game was intended to have a darker tone compared to previous entries in the franchise, and the character creation system was inspired by Sonic fan art the developers had come across over the years. It was announced, alongside Sonic Mania, under the working title of Project Sonic 2017 during the Sonic 25th anniversary event at the 2016 San Diego Comic-Con.
Doctor Eggman attacks a city, and Sonic sets out to stop him. Upon arriving he is attacked by Infinite, a mercenary transformed by the power of the Phantom Ruby from Sonic Mania. Infinite defeats Sonic, and he is taken prisoner aboard the Death Egg. Without Sonic, the land is left without a defender, and Eggman, with the help of his robots, Infinite, Shadow the Hedgehog, Chaos, Zavok, and Metal Sonic, manages to conquer the world within six months. Knuckles the Echidna forms a resistance force with Tails, the Chaotix, Amy Rose, Silver the Hedgehog, Rouge the Bat and a survivor of Eggman's attack whom they nickname the Rookie...
Sonic Forces is an action-adventure platform game similar in gameplay and style to prior Sonic the Hedgehog games. The player's goal is to defeat Doctor Eggman and his robot army. The game features three playable characters: two variants of Sonic the Hedgehog ("Classic" and "Modern"), and the "Avatar" (the player's custom character). Each has unique abilities and attributes: Classic Sonic is restricted to side-scrolling gameplay reminiscent of the Sega Genesis Sonic games and can perform a spin dash on the ground and a drop dash in mid-air to gain speed. Modern Sonic's gameplay follows a similar style to Sonic Unleashed and Sonic Colors: he can double jump, perform a homing attack on enemies, springs, and grappling hooks, and a speed boost by collecting White Wisps. The Avatar is created from a base of seven animal types, which each possess a unique ability; they also wield a grappling hook and can equip weapons known as Wispons, including flamethrowers, whips, and hammers. Depending on the Wispon, Avatars can use temporary abilities by collecting a corresponding Wisp type. Certain parts see players controlling both Modern Sonic and the Avatar, switching between them as necessary, similar to Sonic Heroes.
The game is split into several themed levels, some of which are based on locations from past games, such as Green Hill Zone. Players must complete each level while fighting waves of enemies, and (with the exception of Classic Sonic) seamlessly shift from side-scrolling to third-person perspectives. Stages are filled with features such as spring boards, rails, and boost pads, and obstacles such as spikes, bottomless pits, and robots. Scattered around levels are golden rings, which serve as a form of health: rings protect players from damage caused by robots or other hazards, though they lose their rings upon being hit; being hit with no rings kills the player. The game does not use a traditional life system, instead deducting from the player's score depending on the number of deaths. Players are given a grade dependent on their performance; an "S" rank is the best and a "C" is the worst. Certain levels feature a boss, which must be defeated in order to proceed. Bonus levels can be unlocked by collecting Red Rings hidden in most stages and players may occasionally receive SOS Missions, tasking them with replaying levels with a specific objective.