For the last two years Lovers in a Dangerous Spacetime has been making a splash on the gaming convention and conference circuit. Now, the game finally launches on Steam and Xbox One, bringing its co-op spaceship arcade mechanics to players everywhere.

While its basic premise---two players tasked with rescuing cute animals from fearsome aliens must scramble around a spaceship to haphazardly control different instruments located at different stations---has been unique enough to catch attention, Lovers in a Dangerous Spacetime also showcases lessons for designing an indie game around cooperative play.

At PAX Prime, lead programmer Adam Winkels with Lovers in a Dangerous Spacetime dev Asteroid Base was able to explain some of the unique lessons and design challenges that brought them from game jam prototype to a successful launch.

Design for Player Communication

To start with, Winkels reiterated the game’s design history---when Asteroid Base went into the 2012 Toronto Global Game Jam, he’d been thinking about the spaceship bridge simulator game Artemis, along with the scene from Star Wars where Luke Skywalker and Han Solo are racing through the corridors of the Millennium Falcon, struggling to man the turrets and fend off enemy TIE Fighters.

"Building the single player mode informed our ability to do co-operative two-player design."

Asteroid Base's first prototype closely resembled the final product, with two players racing from station to station in their ship just like Luke and Han. The developer's only major change has been the addition of a map. But Asteroid Base was able to radically improve the co-op experience after the studnailed down the single-player version, in which the other player is replaced by an AI space pet controlled by a Mass Effect-inspired radial menu.

Where Mass Effect used the radial menu to select dialogue choices or direct party AI behavior, solo Lovers players use it to the tell the AI pet which station on the ship to command at that moment.

(Above, via the trailer, a look at the player using the radial menu to point where on the ship the AI pet should move).

"A lot of balancing came from us basically having to always tell the space pet, what to do. Having the cognitive ability to play the game and balance that is what kind of drove that design.”

As a comparison, Winkels talks about games like Resident Evil 5, or Left 4 Dead, which helped inspire Lovers' co-op missions and win states. The philosophy of the radial menu used to control the AI space pet then drove more co-op design for the multiplayer game. Just as Luke and Han shouted instructions and warnings to each other, the radial acts as a stand-in for the natural interaction between players, and helped Winkels and company build and test their new levels.

"Building the single player mode informed our ability to do co-op design," Winkels says. "Once we built that, we'd play the game in that mode and there it's us, the experts, ordering the other person, telling them what they should be doing.”

Their player-controlled pet was able to act as a metric for whether or not their rules made sense in a co-op scenario: could they, experts at the game, effectively communicate what needed to happen to an AI, and could that communication let the expert and the newer player survive the scenario they concocted?

Most often, if that communication with the pet worked, the developers found inexperienced human players could survive as well.

Let Players Pick their Roles

The Lovers team’s biggest design struggle proved to be finding ways to encourage players to take on different roles. “We tried different stuff to encourage that. For instance, when you got power ups, they'd be color coded so only one person could open it and stuff like that. That didn't end up working, it was kind of confusing.”

"Winkels advises testing multiplayer on show floors like PAX, GDC, or indie games festivals, to pick up on the relationship dynamics of different players. Watch players' faces, and you'll see how their normal relationships collide with the artificial systems in your game."

“We ended up saying ‘We'll just let people gravitate to the roles they want to play,’” says Winkels, “Because when we were testing it, people would say ‘I have no interest in doing anything but this. I love doing this part of it, but I don't want to do any other part of it.' And their partner would say 'Yeah I have no interest in driving. I just want to do the other stuff.' We figured we can let people freestyle that.”

For other designers thinking of building cooperative games, Winkels advises testing early and often. But also recommends doing so on show floors at PAX, GDC, or indie games festivals with real players. If you watch their faces, and you'll see how their normal relationship dynamics collide with your artificial systems.

“It’s absolutely a microcosm for the relationship of the 2 people playing our game. If it’s a romantic relationship, you can almost always see who is the person who drives the relationship---it comes through in the game. If you have a parent or a child, you’ll have the kid yelling at the parent, going ‘What are you doing? come on, come on!’”

That energy, Winkels hopes, will help give Lovers in a Dangerous Spacetime and other cooperative games a leg up on sales and on platforms like Twitch--with the yelling, coordination, status reports, and Star Wars references being part of the entertainment both for the players and the people watching.