When Sega was in the hardware business, its stable of
developers enjoyed luxuries like having an intimate familiarity with the
hardware and only developing for one console. In addition, during Sega’s tenure
as a platform holder, developers could petition for hardware changes to assist
“When Sega stopped making hardware, things really changed in
development,” says Sonic Team head Takashi Iizuka. “For everyone in Sega making
software, we were pretty used to and found a lot of upside in being able to be
on our own hardware. If we had requests for our software, we went to our
hardware team and said, ‘Look, I’m making a game like this, I need this to
happen. Make it happen.'”
In the late 1990s, developers approached Sega’s hardware
team about adding a second screen to the controllers that allowed for minigames
on the go. The result was the Visual Memory Unit for the Sega Dreamcast.
However, this wasn’t the first time developers approached the hardware team for
In 1993, the team was in the process of developing the
follow-up for Sonic the Hedgehog 2 with lofty ambitions. “We did 1 and 2, but
the plan going forward to 3 was that we really wanted to hit a home run,”
Iizuka says. “We wanted bigger maps multiple times larger than Sonic 2, but we
also wanted to have more maps; we were having more maps that were also bigger
and take more time to develop.”
Unfortunately, as development continued, it quickly became
apparent the game was too ambitious. Making these larger stages took longer
than the team thought, and several factors came into play to change the course
of Sonic the Hedgehog 3’s development.
The first hurdle the team had to overcome, according to
Iizuka, was a commitment that Sega had made to have a game out to coincide with
a McDonald’s promotion. In addition to that, Sega was quickly discovering the
technology to support its large next game was not in place yet.
“The cartridge sizes were limited in space, so we were
finding out that not only did we have these obligations to get the content out
at a certain time, but we also couldn’t get this massive game that we wanted to
make onto the space that the cart would allow,” Iizuka says.
Sonic Team reluctantly cut the game in half to satisfy these
requirements, but the developers didn’t want the resulting two games to feel like two distinct experiences. The team brainstormed ways to make two separate cartridges feel like one
They went to the hardware division and explained the
situation. The result was to have the Sonic & Knuckles cartridge feature a slot
where you could stack Sonic the Hedgehog 3 to link the two games and make one
long adventure as the developers originally intended. Thus, lock-on technology
Stacking Other Games on Sonic & Knuckles
Though the lock-on technology was designed with putting Sonic the Hedgehog 3 on top of Sonic & Knuckles, Sega knew that players were going to experiment with sticking other games in that slot. The developers had to come up with a contingency plan. The lock-on slot of Sonic & Knuckles would read the ID of whatever cartridge was put on it, so the team tried to have some fun with it. For the vast majority of games, the result is the special “blue sphere” stages from Sonic 3 and Sonic & Knuckles. However, placing Sonic 2 on the top of the lock-on slot gives players something unique.
Placing a Sonic the Hedgehog 2 cartridge on top of Sonic & Knuckles allowed players to play through the entirety of Sonic the Hedgehog 2 as Knuckles, a character that didn’t debut until Sonic the Hedgehog 3. “For Sonic 2, the maps were made so that when you fly around as Super Sonic, you can fly around pretty easily,” says series producer and head of Sonic Team Takashi Iizuka. “The maps are pretty tall in construction, so because of that we were able to fit Knuckles in and play around with him. When we were testing it out on our side, we were like, ‘All right, well let’s take Knuckles and drop him into Sonic 2 and see what happens.’ There wasn’t really an issue, so we were like, ‘That’s a cool little surprise! We should probably leave that in there.'”
Despite the lock-on technology giving players something cool and unique with Sonic 2, the team discovered that the maps from the original Sonic the Hedgehog were not meant for a more vertical character like Knuckles. “We realized that the construction of the world was really made for Sonic the Hedgehog 1 and when you started putting other characters into that world, it didn’t really work right,” Iizuka says. “It didn’t really feel right. So our solution to that was instead of getting you into Sonic the Hedgehog 1 and trying to play with Knuckles or someone else, we didn’t want people to have a bad experience, so we put them into the special stages.”
Unfortunately, advantages such as these were lost when Sega
discontinued the Dreamcast in 2001 and became a third-party developer. “Being
able to make those requests to the people making the hardware that is going to
be running our software was something huge that we were able to do, and when
that was taken away, it was like, ‘I can’t control the hardware anymore! I now
have to make my games within the constraints of whatever the hardware manufacturer
is doing,’ Iizuka says.
Regardless of this challenge, Iizuka and his team remained
optimistic about the leap to reaching a broader audience – an attitude that
carries over into today as Sonic’s exclusivity with Nintendo platforms expires
in time for Sega to publish titles like Sonic Mania and the untitled Project
2017 in the coming year.
For more on the Sonic the Hedgehog franchise, check out other recent stories:
Beta Test How Sonic 3 Became Two Separate Games