A sequel titled Sonic Boom: Fire & Ice is set to release on the same platform during Q4 of 2015.
The game begins immediately after its in-game comic strip prequel, where Amy is in the middle of a fight with Lyric the Last Ancient who wants the info she has on finding the Lost Crystal of Power. After dealing a blow that stuns him for a bit, Amy contacts Sonic to tell him of her findings, only to be knocked off guard by Lyric, (getting disarmed in the process). Despite her protests, Lyric manages to plant a device on Amy's head, knocking her unconscious as he introduces himself to an outraged Sonic. After destroying Amy's communication device with his tail, Lyric makes his getaway.
After completing Seaside Beach, Sonic meets up with Tails, explaining the situation and asking for his help in tracking down Amy. Tails eagerly agrees and reveals his newly-developed form of technology that can allow the viewing of destroyed files. Sonic is glad at this fact, but then wonders how Sticks will react when she learns of Amy's capture. After finding their new friend Sticks the Badger, the duo tell her their current predicament, with Sticks nonchalantly running off to find Amy as they give chase. After a race, Sonic urges Sticks to join the team as teamwork is the only way they can win. Meanwhile, Tails manages to decipher some of Amy's research logs, which prompts them to head for the Scrapyard, where Knuckles last was. The group finds Knuckles without much trouble and the echidna is eager to help, claiming that they should get a move on. With the full team assembled, the group heads for Shadow Canyons, where they notice Shadow the Hedgehog standing off in the distance, only to run off. Wondering what he is up to, the group follows him, and after a race, he comes back to his senses and everyone realizes that he's been possessed by Lyric this entire time via a mind control device similar to the one used on Amy. After being taunted by a hologram of Lyric that comes from the broken device, Shadow skates off in hot rage, with the others agreeing to follow him into the Ancient Ruins.
After completing Ancient City, the group discovers that a large robot facility is hidden beneath the ruins, and is responsible for all of Lyric's robots. They decide to shut it down, and are ambushed by Metal Sonic while down there. Sonic races him, but loses and Tails shortly manages to track his movements and find that he is headed for the Volcanic Crater. Once there, the team finds themselves lost, but decides not to give up. After deciphering another of Amy's logs, they discover that a hangar of ancient planes is hidden in the volcano and decide to search for it. After finding it, the group heads off, and manages to escape the volcano, though Tails has some trouble steering the plane and ends up crash-landing on the Cloud Sanctuary, (much to an airsick Knuckles' relief). Meanwhile, it is revealed that Amy has regained consciousness and is adamantly refusing to translate the ancient language for him despite his orders, all the while claiming that Sonic and co. will come for her.
After Sonic, Tails, Knuckles, Sticks, and the freed Amy finally arrive on Lyric's airship, they being to flaunt the power of teamwork in front of the dastardly snake, only for Lyric to get an idea and trap everyone but Sonic in the same glass ball that Amy had been imprisoned in previously. Sonic gives chase, and after fighting Lyric, he frees everyone. Their rejoicing is cut short however, as Lyric regains consciousness and prepares a giant robot to finish the group off. Shortly later, Shadow intervenes and dismantles the mech, rendering it useless and kicking Lyric out the bomb-doors of his own ship (which Sonic had opened just as this happened). The team rejoices again, as Sticks gives a slightly incorrect speech about teamwork. The adventure over, Shadow walks off, claiming to be a loner and superior to Sonic. Sonic is dismayed over the fact that Shadow does not want to join them, as he thinks that he would make great addition to "Team Sonic". Sonic and Knuckles then get into a brief argument over what the team's name should be as the group begins the long journey back home.
Sonic Boom: Shattered Crystal is a 2D side-scrolling adventure platformer. Unlike its Wii U counterpart, which is more focused on 3D platforming and beat-em-up, Shattered Crystal places a bigger emphasis on platforming and puzzles, while each character has their own unique abilities to get them through the levels. There are three different types of stages in this game: Adventure levels, which take up the bulk of the game are large, mostly non-linear stages in which the player can control all four characters (though only Sonic is available from the start). Rival Races are also from the 2D perspective. In these levels, you must race another character through a linear but lengthy course. Finally, there are Tunnel levels, which take place in 3D and are completely on rails. Here, the player is stuck at a full run, and must move left and right to dodge obstacles, occasionally having to jump off the track and use the Enerbeam to grab onto a rail in order the cross a chasm. In the latter two stage-types, only Sonic is playable.
The bottom screen of the 3DS has three uses: A character-select screen allows the player to tap on the portraits of the four playable characters in order to switch to them on the fly, (though they can also be switched to by pressing their corresponding direction on the D-pas. There is also a map screen that shows the entire level in a Metroidvania-esque map format that highlights various things in the level, including collectibles, checkpoints, slingshots that separate chunks of the level from each other, and the level's exit, as well as showing the percentage of the map that has been explored. Finally, there is a Level Stats screen that shows how many of each collectible have been collected and the time and ring records of previous playthroughs of the level in question.
The game contains a variety of collectibles, with some of them unlocking special content for Rise of Lyric via connectivity between the two games. Game progression revolves around moving along a world map broken up into several islands, as well as the collection of emblems (34 in total) in order to access new levels on the world map. Collecting every emblem in the game unlocks Amy's house, where the player can enter and watch all five characters dance to a random piece of music from the game. Each adventure level has three emblems that can be earned from it, (along with two tokens which are not crucial to progress through the game), while the other types only have one emblem plus the two tokens. These can all be earned in the following ways:
Simply clearing the level - Every level (regardless of its type) rewards the player with an emblem simply by completing it.
- Collecting all of the crystal fragments - Crystal Shards are only found in adventure levels, and each level has a total of 5. Collecting all 5 unlocks an emblem. There are 40 of these in total, and when they are bought to Sticks' burrow (not available until Sticks is unlocked) she can repair the Lost Crystal. Additionally, the restored shards will fill in various spots on the crystal, causing them to glow and also affecting the way the top screen looks during a loading screen. After collecting all 40 shards, the player earns a purple token that can be used to purchase a rare figurine that can't be bought via any other methods.
- Collecting all of the blueprints - Like the crystal fragments, these are only found in adventure levels, and each level has a total of 6. Collecting them all earns the player an emblem. There are 48 blueprints in total, and 6 of them are required to earn an upgrade to the game's assets; (upgrades are earned by taking the set of 6 to Tails' workshop, which can't be accessed until Tails is unlocked). Three of the upgrades are for the map. "Map Accelerator 1.0, 2.0, and 3.0" allow uncollected blueprints, uncollected crystal fragments, and ring/shield monitors respectively to be highlighted on the map. The rest of the upgrades are for various gameplay mechanics. The "Shield Award" allows the player to automatically gain a shield upon passing the first checkpoint in a level, the "Ring Defense" allows the characters to lose 25% less rings when they get hit, the "Ring Attractor" allows characters to instantly draw in nearby rings, the "Mega Grapple" allows the player to instantly kill shielded enemies just by ripping off their shields with the Enerbeam, and the "Mega Sprint" allows players to insta-kill grounded enemies just by sprinting into them (similar to the Sonic Boost from the mainstream games). All of these upgrades can be disabled and enabled at will.
- Clearing the level in a certain time - By clearing the level in question within a certain time, the player can earn a token. The time requirement for adventure levels is 5 minutes, while it varies for rival races and tunnel levels.
◾ Clearing the level with a certain number of rings - Like the above, a token is earned if the level is completed while the player has a certain number of rings. The ring requirement is 100 for all adventure levels, and 250 for the tunnel levels, while it varies for rival races. Tokens collected through both of these methods can then be spent at Q.N.C's toy shop, (with one location on every island), where paying just one will unlock a figurine. There are over 40 figurines in total, with one rare one that can't be unlocked without using a method mentioned above. Tokens cannot be earned more than once on the same level.
Other ways to get tokens include connecting with other players via StreetPass, and visiting Knuckles' hangout on the world map, (not unlocked until Knuckles is unlocked as a playable character, and only visitable every 24 hours) where you can input button presses to help Knuckles break a punching bag and gain the token inside.
- Roger Craig Smith as Sonic the Hedgehog
- Colleen Villard as Miles "Tails" Prower
- Cindy Robinson as Amy Rose
- Travis Willingham as Knuckles the Echidna
- Nika Futterman as Sticks the Badger
- Kirk Thornton as Shadow the Hedgehog
- Patrick Seitz as Lyric the Last Ancient