I've had a number of ideas over the years. Must of which have been rubbish. But there is one that I've been thinking about on and off again since around 2010 or so. A Sonic the Hedgehog reimagining. Not my favorite series, but I've just been wondering how the series can best be represented in a 3D setting, and have had a few thoughts.
Opening Thoughts: This theoretical game would be meant to emphasize the historic strengths and attributes of the Sonic series while downplaying the faults. Traditionally, this series has been at its best when gameplay is able to be fast. However, the Sonic series is not just speed. Though they are often derided, many of the better received Sonic games make use of the wide ensemble of Sonic's furry friends. Looking back, people like the Adventure duo, Advance trilogy, and other games where Sonic didn't monopolize affairs. Soundtrack and general presentation are other strong points for the series. Players know they are doing well when they can baze through levels.
Weaknesses for the Sonic series have also been well documented. A major recurring complaint across entries is a lack of control, especially where platforming is concerned. Even in better received games like Sonic Colors, platforming isn't considered as tight as in many other games. Story is a weird problem, as Sonic's stories are either overly complex and full of plot holes or quite simple. The series emphasis on speed means collection elements need to be handled carefully. An overemphasis on playstyle diversity can lead to a 2006 style disaster. And though speed is hard to stick with, Sonic Boom showed that platforming and combat are not necessarily viable alternatives.
Name: Sonic Island
Concept: A reboot/reimagining of the franchise as an open world game. Story elements and characters are taken from Sonic games ranging from 1991 to 1998, with Sonic Adventure being the borderline game.
Structure: The game takes place on an island divided in a ring of perhaps six regions surrounding a seventh central area. Each region has a boss to defeat, which grants Sonic a new ability for accessing future areas and collecting bonuses. Some choices for what to do next will be available. The island has to be big enough to contain plenty of things to run by and discover, even for a speedster like Sonic. This means that there need to both be obvious roads to blaze through and paths to wander down.
Regions: The six or seven regions would likely be themed like in many Sonic games, but not all themes would be good ideas. For example, water sections are probably a bad idea. I'm thinking the opening region would be a grassy and beach-themed area like in many opening Sonic levels. Just don't make a killer whale a setpiece. The central region can be the standard Lethal Lava Land mixed with evil laboratories. What types of regions occur later depend on Sonic's collected abilities. Sonic naturally starts with the ability to run fast and jump on enemies to beat them, but maybe he doesn't become immune to fall damage before the cliff-heavy mountain region. Maybe the Spin Dash is the first new ability, and lets Sonic go through lines of enemies. Maybe if a water section DOES pop up, Sonic gets the ability to run on water beforehand. Maybe he gets the ability to dash through solid walls at some points, tying into puzzle solving in the game by figuring out how to gather momentum.
Each region would be populated by existing Sonic characters, with unique interactions and things to offer, be they items, missions, info, or whatever. The large cast can be used to populate the island without overwhelming the player.
Characters: Most of the game is spent playing as Sonic, with up to two other characters being playable for specific sections. Since Sonic is the mainstay character for travelling across the island, the other characters would have to stand out. Perhaps Tails could be used for sections with more precise platforming, using his hovering abilities, and Knuckles could emphasize 3D environments with combat like in Sonic Adventure. Sonic himself would be best at quickly traversing environments, but would also be a decent fighter. He could emphasize evading enemy attacks and manuvering into better positions to attack from, be it against a single armored titan or a swarm of enemies.
Rings: Rings are tricky because they are rubbish as a helath system. Sonic is fast-paced, so healing should not be a tough affair. Maybe Sonic should alwas have low health which recovers automatically? This game would be a better use of the mechanic than most. As for Rings, they can be used as in-game currency or to upgrade certain abilities.
Characters: Sonic would be the obvious main character, opposed by Eggman. He would be supported by Tails, the player's main aide in the game, and rivals with Knuckles, who seems to have been awesome back in the day. Besides that, all those annoying minor characters would still have roles to play. Amy Rose can be used as a recurring source of info o objectives. The Chaotix can provide the local story arc for one of the regions. Nack the Weasel could be an unwitting pawn of Eggman at one point sent to fight Sonic. Big the Cat could be in charge of a peaceful fishing minigame or a collectathon. Metal Sonic could be a major boss, possibly fought in the obligatory Super Sonic Final Battle. Hell, throw in the real oddballs like Ray the Flying Squirrel from SegaSonic, Wendy WitchCraft from that GameGear spinoff with Tails, and so on.
