When you're building a video game prototype, it's always a good sign when it's just immediately fun from the get-go. When the team at Quebec-based Frima Studio first put together the stick-figure demo that would later become Chariot, there were smiles all round.

The Frima team had been exploring couch co-op experiences, and what worked best as a means for getting two people fully immersed together in a console game. What sort of experience brought players together, while simultaneously causing hilarious arguments that only a local multiplayer game could?

"People who played together argued about which way to go and how they should attempt to reach this or that area," says Chariot producer Martin Brouard of that original stick-figure prototype.

"They would make all kind of faces when playing, and onlookers would cheer them when they performed an impressive maneuver, and laugh at them when they failed miserably," he continues. "This was exactly the kind of couch co-op experience Philippe Dion [Frima's lead programmer] had in mind when he initially proposed the idea to me."

As seen in the video above, the first prototype encapsulated much of what Chariot would eventually become, albeit with carefully considered puzzles and gorgeous visuals. What the Frima team found themselves really needing was a context for this mechanic.

"Why are the players carrying a chariot through these caves?" Brouard questioned. "Because it's fun of course, but we also really wanted to create a charming game experience that players could lose themselves in."

Numerous ideas were thrown around, including the idea of a guild of Charioteers gathering loot to boost their kingdom's war efforts, and rather bizarrely, the pairing of an anthropomorphic frog wizard and an escaped convict.

Eventually the team settled on the idea of a princess carrying the remains of her royal father to a final resting place, with her careless fiance in tow.

"The father and daughter element came up when discussing the two playable characters," notes the producer. "I have three daughters who love games, and I thought it might be interesting to have this cool father-daughter relationship between the protagonists."

This was when the idea of essentially having the chariot itself as a third character came about, guiding your path through the mines.

"Since the players carry the chariot around at all time, we wanted it to act as some sort of third protagonist, a non-playable entity that the players would care about," says Brouard. "That's when we came up with the idea of a haunted casket on wheels. While that might sound a little grim, it was always clear to us that the king's ghost would bring a lot of comic relief to the game. The guy is an hypochondriac ghost obsessed with being buried in a beautiful tomb full of riches..."

The team wanted a fearless woman to be a playable character, and finding her a companion to complete the co-op arrangement then took precedence.

"We designed her fiance as a trustworthy, if a little careless, companion," Brouard muses. "These two might be carrying a coffin over lava pits and endless chasms, but they are having a lot of fun doing so together."

"You could say it's somewhat inspired by courtly love, and that the king's ghost acts as a chaperone so that this stays family friendly," he laughs. "In terms of gameplay, we also wanted to slightly differentiate the two playable characters. To emphasize her fearless nature we decided to equip the princess with a sword, making her the melee fighter and the fiance with a sling, acting as a ranged attacker."

Chariot is due to release for PlayStation 4, Xbox One, Nintendo Wii U and PC this fall.

[Mike Rose wrote this article for sister site Gamasutra]