Sonic Frontiers is as much a loving homage to the rest of the series as it is an innovator with fresh ideas. Longtime Sonic fans are richly rewarded for sticking with the blue blur through all his highs and lows in writer Ian Flynn's thoughtful and detailed script work.
If you fear you've missed out on some Sonic lore referenced throughout Frontiers, TheGamer has you covered. From less-appreciated spinoffs like Sonic Spinball to more contemporary entries like Sonic Unleashed, Frontiers is full of little nods and callbacks to previous titles in the series.
13 Amy Rose, Fortune-Teller
One lesser-known element of Amy's characterization dates back to Sonic CD — she was originally slated to be a fortune-teller, perhaps with tarot cards (referred to in Frontiers as "fortune cards"). Unfortunately, that detail faded away with time as the series progressed, and the character continued to change hands among many writers.
Ian Flynn reintroduces this aspect of her personality for a refreshing, more well-rounded take on the character, who believes in the power of love and good fortune to make the world a better place. It's no wonder Amy's boundless compassion and uncanny intuition led her to connect with unlikely allies such as E-102γ in Sonic Adventure, and even Shadow in Sonic Adventure 2.
12 "End Goals"
In one of the game's funniest exchanges, Sage asks Sonic "what are your end goals?", to which he cheekily responds "oh, sometimes they're tiny signs that spin around, or big gold rings".
Fans know well that almost every stage in previous Sonic games is always marked with one of these objects to signify the end of the level (with a few notable exceptions in games like Sonic Rush Adventure, for example, which features a spinning treasure chest full of precious gems). Sonic's goals and his "end goals" tend to go hand-in-hand.
11 Chaos Zero and the Ancients
It's obvious that the Ancients are meant to visually echo the design of Sonic Adventure's most striking characters: Chaos 0. In Eggman's personal record, called the Egg Memos, entry 11 confirms that the Ancients and Chaos are genetically related to one another.
Players speculate that Chaos is in fact (or was) the last of the Ancients, still living after the catastrophe that wiped them out, and that the absence of his Koco caused him to lose his coherent thoughts and personality.
Chaos is left only with the base instinct to protect the Chao and the Master Emerald, which sends him into a violent rage when Knuckles' ancestral echidna tribe attacks the shrine on Angel Island.
10 Volcanic Pinball
Sonic hypothesizes that "the love of pinball predates civilization", and he may be right. One of the Ancients' seals protecting them from a Titan gone amok takes the form of a pinball level, located inside a volcano. This is likely a reference to Dr. Eggman's Veg-O-Fortress in Sonic Spinball, the original Sonic pinball spinoff for the Sega Genesis.
Infamously, the entire game takes place inside a volcano that Eggman has repurposed for his animal-roboticizing needs, which was perhaps not the most ideal terrain for a pinball game.
9 Islands of the Past
Accessed via Big's fishing minigame menu, Egg Memo 3 mentions that the Starfall Islands' Cyberspace areas seem to feature recreations of South Island, West Side Island, and Angel Island. These are, respectively, the settings for Sonic The Hedgehog 1, 2, and 3 (& Knuckles).
In particular, Dr. Eggman is specifically referring to the Cyberspace levels pulling their visuals from Green Hill Zone, Chemical Plant Zone, and Sky Sanctuary Zone, manifesting memory data from Sonic and friends' presence in the digital world.
8 Maria!
Sage, Dr. Eggman's AI assistant-turned-lovable-daughter, has some similarities to Maria from Sonic Adventure 2. Much like Maria, Sage is naive to the mechanisms of the real world, and has a deep compassion for living things, even among her adversaries.
Eggman specifically mentions that Maria is his cousin in Egg Memo 17, and regrets that he was never really able to meet her due to certain... circumstances, let's say, aboard the Space Colony ARK.
Maria was of course much younger than Eggman himself when she died, and his knowledge of her through his grandfather Gerald Robotnik's memos may have awakened something of a paternal instinct beneath the scientist's pompous facade.
7 Maps Within Maps
Cyberspace level layouts reference previous Sonic stages, and often with a twist. While the visuals belong to one of four core areas from Sonic's past (Green Hill Zone, Chemical Plant Zone, Sky Sanctuary Zone, and a Speed-Highway-Empire-City mélange), the physicality and skeletal map of other levels hide beneath the surface.
Cyberspace level 2-6, for example, is visually modeled after Green Hill Zone, but the structural layout is borrowed from Sonic Adventure 2's Sky Rail. This creates an interesting uncanny valley effect tied to your muscle memory, much like it would for Sonic himself navigating fractured reflections of his past.
6 With Friends Like These...
For the first time in recent memory, Knuckles' friendly rivalry with Sonic characterizes the thematic core of Sonic's interactions with him. The game even features a screenshot of the opening cutscene from Sonic the Hedgehog 3, their first meeting (in which Knuckles bursts out of the ground, punches Sonic, and steals all the Chaos Emeralds from him; what a nice guy!).
Knuckles aims many playful jabs at Sonic throughout their time together on Ares Island, while the two simultaneously boost each other up when the situation goes south.
5 Tangle's Mainline Debut
Originally created by Ian Flynn for the IDW comic series, Tangle the Lemur is the first character from one of Sonic's many published comics to ever make it into the mainline game canon — Sonic mentions her by name in one of Frontiers' cutscenes.
Designed by Tyson Hesse of Sonic Mania fame, Tangle is a no-nonsense fighter who accompanies Sonic on his more dangerous adventures. With Tangle's creator at the helm of the Frontiers script, and likely its teased sequel, perhaps more of the IDW comics universe will be present in future mainline titles.
4 More Powerful Than The Eclipse Cannon?
On Chaos Island, Tails mentions that some of the ancient weapons he and Sonic have found may be more powerful than the Eclipse Cannon. For the uninitiated, the Eclipse Cannon is a major plot element in Sonic Adventure 2, located in space — it is, as the name implies, a very large and frightening laser beam cannon powerful enough to take a sizable chunk out of the moon.
It just so happens to be attached to the Space Colony ARK, a space station made in the style of a Bernal Sphere. Defeating Frontiers' true final boss, The End, on hard difficulty is also evocative of the Finalhazard fight at the Sonic Adventure 2, with similar lines of pink bubble lasers that can be lethal to reckless players (and a visual echo of the Space Colony ARK plummeting towards the earth).
3 Sonic Knows A Time Traveler
Continuing the tradition of referencing characters from different Sonic media, Silver the Hedgehog from ill-fated Sonic 06 is mentioned in reference to Sonic "knowing a time traveler".
He could also be talking about Blaze, who accompanies Silver to the future in Sonic 06, but Silver is more well-known as a time traveler of the two. It must look pretty great on his resume. After all, Silver did travel to the past to correct the mistakes he made in 06 and save his friend Blaze from another dimension.
2 Electric Speed
When Sonic collects the maximum amount of rings in Frontiers, he appears to be surging with sparks of electric energy that majorly boost his speed. This is likely a nod to the Sonic movie adaptations, which conceptualize Sonic's speed and Knuckles' strength as jolts of mysterious electricity.
Is the power of rings connected to the power of the Chaos Emeralds? Given that Super Sonic needs both of these things to maintain his form and kick butt, it's possible. Perhaps more will be revealed in the upcoming third installment of the Sonic movie canon.
1 Chiming In
Fitting in a game where Sonic inherits the paraloop ability (called the Cyloop in Frontiers) from his distant gameplay cousin, NiGHTS, the Koco make a particular chime sound when they move that is in fact borrowed directly from NiGHTS Into Dreams.
It's the sound that plays whenever Nights successfully flies through the center of a ring, albeit pitched a bit differently for the Koco. Many of the aerial Super Sonic boss fights have a bit of NiGHTS DNA in them as well — dynamic flight and in-air Cylooping makes Frontiers something of a loving homage to the series.