SegaSonic the Hedgehog is Sonic the Hedgehog's first Arcade Game (not counting his appearance as an inanimate object in Rad Mobile, or the also-Japan-only Waku Waku Sonic Patrol Car kiddie ride), released in 1993. 1 to 3 players can choose between Sonic and his friends, Ray the Flying Squirrel and Mighty the Armadillo, to escape from Eggman Island while the doctor sends all sorts of traps to run over them. As a unique element, character movement was handled via a trackball instead of the typical joystick, allowing the player to maneuver the characters in a very fluid fashion (a precursor to analog controls). However this trackball system has also resulted in issues bringing this game out in any other form.
The objective of each level is to get away from whatever is chasing you while dodging thematic obstacles and trying to collect as many rings as possible since they recover HP, give you a health bonus if you collect more than 50% of them and are also the only things that increase the score.
This is also the first Sonic game (alongside Sonic the Hedgehog CD) to have voice acting and dialogue for the characters. The game has never seen a release outside of Japan (even though there is English text and sprites to suggest localization was meant to happen). Sonic's companions from this game faded into obscurity following this gamenote until 2018's Sonic Mania Plus, where they were added as additional playable characters with a more diverse moveset than they had in this game.
This game contains examples of:
- Advancing Wall of Doom: The very first thing chasing the heroes during gameplay, and flames.
- Alliterative Name: All level names, except for Eggman's Tower.
- Badasses In Distress: Sonic, Mighty and Ray are kidnapped by Eggman at the beginning of the game, so the game starts when they break out of their cell and fight their way out of Eggman Island.
- Big Fancy Castle: Trap Tower and Eggman's Tower.
- Boss Battle: Just one, in Landslide Limbo - and it's a hard one!
- Bottomless Pits: They surround the heroes most of the time. If you run into them, you usually have a chance to turn to the other side before falling for real.
- Chuck Cunningham Syndrome: Ray the Flying Squirrel vanished completely from the Sonic game continuity until 2018's Sonic Mania Plus. He was, however, given a reference in Sonic Generations.
- Death Course: The entirety of Eggman Island is one, with traps and hazards everywhere to kill Sonic and his friends off.
- Death Mountain: Landslide Limbo.
- Disney Villain Death: Eggman falling into the ocean in The Stinger, of course he's not gone for good, as he points out while doing so.Eggman: Why does it always end this way?...
- Divergent Character Evolution: Like the previous SegaSonic arcade title, SegaSonic Bros., a red and yellow alternate for Sonic are utilised. Here however they are redesigned into unique characters of different species to Sonic; Mighty and Ray.
- Early Installment Weirdness:
- The game's title is a result from Sega of Japan's early use of the "SegaSonic the Hedgehog" branding in various Sonic-related products, due to fear of getting sued by Taito for using the "Sonic" branding given that they had recently released a game called Sonic Blast Man.
- Rings don't drop when Sonic and co. take damage in this game, accumulating from stage to stage instead as something akin to a score total. They also heal a genuine health bar, which otherwise only appeared in fighting games since.
- Escape Sequence: The whole game is this. Given that the setting is Eggman Island.
- Evil Laugh: Dr. Eggman does this all the time. And it's not his usual "hohohohoho".
- Game-Over Man: Dr. Eggman will laugh evilly at you after your game is over by getting killed; if your game is over by having completed all 7 levels, he instead swears revenge.
- Gotta Catch Them All: You can recover some health if you beat a level with 50% or more of it's rings.
- Hit Points: If they reach zero, the character dies. Rings in this game only recover a bit of the health bar.
- Lethal Lava Land: Volcanic Vault.
- Indy Escape: A giant boulder appears at least twice.
- Nintendo Hard: The game lets you continue as much as you want, besides the Point of No Continues below, but actually trying to not die is far easier said than done. Numerous traps and sections boil down to Trial-and-Error Gameplay as you soak up damage, or sharp reflexes and a second or two to spare, and each continue only has one life in the first place. A 1CC run is genuinely impressive.
- Noob Cave: The first area. You can't even die in it!
- Non-Indicative Name: As with his later appearance in Knuckles Chaotix, Mighty doesn't do anything that would reflect his namesake, being entirely speed-centric. It wouldn't be until Sonic Mania Plus that he was given moves and abilities that reflected his physical strength.
- Not-So-Harmless Villain: Eggman is plain out relentless in this game, outrunning and trapping Sonic and his allies with his mech at the very start of the game, and then placing them in a non-stop marathon of Nintendo Hard booby traps throughout Eggman Island. A huge amount of animations from Sonic and co look panicked and frantic, making clear this is not the usual runaround Sonic is used to against Eggman.
- Oh, Crap!: The trio's expressions clearly read this as Eggman's vehicle closes in on them in the intro.
- Point of No Continues: You can't continue nor have any more players to join in once you reach the final area of Eggman's Tower. If you get killed by the flames without beginning the Timed Mission, you'll get to see your character's death animation; should you fail to escape before time runs out, you'll be told that "YOU FAILED". In both cases, your game will be over for real!
- Power Trio: Sonic, Ray and Mighty.
- Shifting Sand Land: Desert Dodge.
- Slippy-Slidey Ice World: Icy Isle.
- Spiritual Successor: The game's design is based on Marble Madness.
- Super Not-Drowning Skills: The trio can breathe underwater... forever?
- The Many Deaths of You: The characters have various hurt/death animations.
- Under the Sea: Wild Water Ways.
- Villain: Exit, Stage Left: Upon finally reaching Dr. Eggman, he just activates the self-destruction sequence and runs away.
- Winged Soul Flies Off at Death: Upon running out of HP.