Sonic Mania arrives this week. It's a paean to Sega’s mascot and his most popular games from the 90s. But this is not another stab by Sega at revitalizing Sonic’s legacy; it’s something altogether more interesting, the end result of a long path taken by hobbyist coders inspired by their old favorites.
Sonic’s new game was built by a team who dug into the very underpinnings of the hedgehog’s 16-bit classics. Gamasutra talked to Simon Thomley at Headcannon and Tom Fry at PagodaWest Games for insight into their methods, their relationship with Sega’s classics, and how porting retro console games to mobile phones helped prepare them build the most well-received Sonic game in ages.
In the early days of the App Store, ports of console games to phones proliferated. The name and title screen might have been the same, but once the action began the experience... fell apart. Virtual buttons, frame-rate issues, and low quality control made a mess of such classics as Mega Man, Pac-Man, and more.
So when Thomley and Melbourne, Australia-based developer Christian Whitehead helped deliver a note-perfect version of Sonic CD to the iPhone and Android stores in 2011, it was a revelation.
Sonic CD for iOS
"We had both wanted to work with the franchise for a long time."
Thomley had been making his own personal projects since 1995, building them from the ground up in C. Whitehead, a fledgling developer himself, was impressed and inspired by his work; he reached out to Thomley in 2000 and began a back-and-forth as they each built their own games.
It wouldn’t be until 2009 when the two collaborated on the Sonic CD project, which began as a kind of hail mary pass to get the attention of Sega. A video of an early prototype level “Palmtree Panic 1” got a lot of attention; the right people saw it, and soon Whitehead was in touch with Sega.
“We had both wanted to work with the franchise for a long time,” Thomley tells me. “Christian had recently shifted his focus to iOS development, and with Sega re-releasing their classics on mobile, Sonic CD seemed like an excellent opportunity to build a working relationship.”
Sonic CD for iOS
"Instead of emulating the convoluted, archaic architecture of the Sega CD, Whitehead and Thomley studied the original game’s anatomy in order to re-build it using new materials."
Because that title was originally built on Sega CD hardware, Sega’s mobile division couldn’t use the same code base they’d used to bring other Genesis classics to the App Store.
Whitehead asked Thomley to help him with the demo, knowing his ability to build impressive games from scratch. “We had the capability to recreate it specifically for the platform,” Thomley says.
One reason the game succeeded beyond other ports was that it was built from the ground-up using a new, proprietary engine that Whitehead developed called the “Retro Engine.”
Instead of emulating the convoluted, archaic architecture of the Sega CD, Whitehead and Thomley studied the original game’s anatomy in order to re-build it using new materials.
The process was less Frankenstein’s monster and more Dolly the Sheep. Whereas previous Sonic games lumbered slowly and laboriously on mobile, Sonic CD was fast and zippy, a near-perfect clone of the original. And because they now had a modern language to write in, they could expand what the game could do, adding modes and features a modern player expects.
All that effort pays off. The fruits of this early labor are clearly seen in Sonic Mania, a game that feels like the original Genesis games but is expanded, polished, and remixed into something new. Just as young writers are asked to copy their favorites in order to understand the rhythm and feel of a beautiful sentence, developers can look to the very DNA of classic games to teach them how and why a game works.
"I've pretty much been researching for this project for the last 26 years."
Tom Fry, art director at PagodaWest, has been studying that same classic game DNA all his life. “I've pretty much been researching for this project for the last 26 years,” he says.
That familiarity is evident in PagodaWest's well-received series of classic retro-style titles, like Major Magnet. “The wealth of knowledge amongst our team is so vast that between us, we have the entire tapestry of Sonic on the back of our hands.”
It helped Thomley know when something was off with their Sega project. “When playing the game, you can see the effect, but not the process,” he explains. “For our Sonic remakes, it was important that anyone who has ever played the originals notice as few differences as possible based on gameplay input. The result of any action must match the original result of the same action.”
Thomley scoured their new version of the original code, making sure that specific blend of physics-based action and speed aligned with player expectations. If a single number value was off, the experience could be ruined.
"The way the graphical assets are rendered borrows many techniques that were used on Sega Mega Drive, Saturn and other consoles of these eras."
Fry knew Sonic Mania had to not only feel authentic, but look right. “The way the graphical assets are rendered borrows many techniques that were used on Sega Mega Drive, Saturn and other consoles of these eras,” he says, “such as the use of palette-indexed sprites and levels which are constructed from thousands of tiny 16 x 16 pixel tiles."
Fry adds that these were "all memory saving techniques employed back in the day which allow the game to perform at a rock solid sixty frames per second, even on lowly hardware and with little to no loading times today.”
Notable independent releases of the last few years have often been anchored by a game decades in the past. Axiom Verge by Thomas Happ is built on the bones of Nintendo’s Metroid franchise, just as Shovel Knight by Yacht Club Games is an amalgam of Duck Tales, Mega Man, and Zelda 2. But those new games succeed beyond mere mimicry into establishing their own identity.
Sonic Mania is a new game, built by indie devs outside of Sega, determined to feel exactly like a classic Sonic game. The goal is not to evolve the franchise but reach back into the past and find what we once loved. Sega and Sonic Team put their trust in Headcannon, PagodaWest, and Whitehead, but kept a close eye on proceedings.
“We worked with Takashi Iizuka and Kazuyuki Hoshino of Sonic Team to keep things in line,” Thomley says. “But for a project of this scope, we were met with surprisingly few objections.” Any additions had to feel moored to Sonic’s origins. The biggest difference between Mania and previous attempts at evoking the 16-bit style may be that Mania is not a reinvention, but rather a continuation.
"I was keen to give it a more Saturn-esque, ‘32-bit’ feel by enhancing the color depth and doubling, maybe even quadrupling the frames of animation."
“The marketing for Sonic 4  posed the idea of, ‘What if we made a new 2D Sonic game today?'" Thomley points out. "Whereas with Sonic Mania, we asked ourselves, ‘What if they made a new 2D Sonic game in 1995 or 1996?’”
With the advent of 3D games, developers were chasing this new dimension, trying to build the next new thing. A 2D Sonic game releasing in 1996, the same year as Super Mario 64, would have been commercial suicide.
Today, though, 2D games coexist alongside massive open-world adventures. The marketplace has learned to embrace its past. Sonic Mania gives fans a chance to play that alternate timeline sequel that never was.
Much of that has to do with Fry’s art. “I was keen to give [SM’s graphical assets] a new lick of paint,” he says, “in order to give them a more Saturn-esque, ‘32-bit’ feel by enhancing the color depth and doubling, maybe so much as quadrupling the frames of existing animations and adding entirely new animations into the repertoire.”
To Thomley, the hope was “to create was something that gives the sense of a long-lost Sega Saturn game, something that fans of the Genesis originals might have expected as a next step.”
Retro isn’t going anywhere. If anything, old games are growing in popularity, with modern systems frequently getting re-releases of games such as HAMSTER’s series of Neo-Geo titles, not to mention the phenomenon of Nintendo’s classic miniature systems driving people into fits of madness.
Sonic Mania hopes to inspire in its players another kind of madness: That strange feeling of being transported to another time, one you might have forgotten, or worried you’d never see again. And with the help of archaeological developers like Whitehead, Headcannon and PagodaWest, we can look forward to plenty of retro mania in the years to come.