The game's creator, Strife, admitted that her attempts at designing a protagonist for her newly started project failed. After searching through DeviantArt, she found the character that would become the main heroine of the game. Sash Lilac started off as a Sonic fan character, created by artist Ziyo Ling in 2001. Strife asked Ziyo for permission to use Lilac in her (at the time unnamed) fangame and she eventually agreed to.
Not that long after the first demo of the game was published, Lilac was criticized for looking too much like Sonic, as she was also a hedgehog, which led to Strife attempting to change her design. She was initially hesitant about changing her sprites permanently without a unanimously approved redesign.
During that time, it was decided that Lilac would be changed into a water dragon and eventually, Strife settled on the version of Lilac seen in the final game. Despite the design changes Lilac went through, a few of her traits, like her long hair and martial arts skills, were unchanged from her original version.
I took the opportunity to ask her if I could use some more of her Sonic OCs to balance out the hero/villain ratio.— Sabrina DiDuro (Strife), December 22nd, 2011, on soahcity.com/forums
Before Strife got permission to use two other characters from Ziyo (in that case, Carol and Milla), the second main character used to be a black cat with blond hair and an orange shirt. After she was permitted to, she drew Carol over the existing character sprite.
Carol as seen in the August 2012 Prototypes.
Serpentine first appears in early prerelease footage seen riding on the snake boss of Dragon Valley. Initially, he was designed as a slug and was, at that time, nameless himself. The August 2012 Prototypes simply refer to him as the "Serpentine Rider".
As for the snake character, he's actually supposed to be a slug. xD— Sabrina DiDuro (Strife), November 16th, 2011, on soahcity.com/forums
A safe assumption would be that, since people have mistaken him for a snake, Strife decided to change him into a viper, and gave him the snake boss' original name.
Spade the Cavy. He'll either be an anti-hero fighting against the main villain or one of his strongest mercenaries, but either way, he's Sash Lilac's rival. He'd attack using a deck of playing cards, which provide different effects depending on how the suits are combined.— Sabrina DiDuro (Strife), October 17th, 2011, on soahcity.com/forums
Spade, first shown in October of 2011, was originally designed as a cavy but later changed to be a panda. The hair, ears, and the red scarf resemble the King Shadow Ninja from LaTale, while the shoes were similar to Shadow's from the Sonic series before being changed for that reason.
- FP SpadePanda.png
Concepts by Strife about turning Spade into a panda since his design was too sonic like.
- The Evolution of Freedom Planet - IndieDB.com, Aug. 12th, 2012
- My Sweet Purple (archived) - DeviantART.com, Aug. 19th, 2006
- Lilac Revamped! - IndieDB.com, Aug. 25th, 2012