When Facebook Instant Games rolled out in November 2016, EverWing was one of the smoothest and most feature-complete launch titles available.

A vertically-scrolling shoot-'em-up, EverWing is a game that's easy to play in short bursts but also allows the player to carry progress and upgrades across multiple sessions.

Amidst a raft of fairly rudimentary experiences and arcade ports launching alongside Facebook's HTML5-powered gaming augmentation of its Messenger app, it immediately stood out.

One reason for this is that its developer, Blackstorm Labs, was set up specifically to create - and facilitate the creation of - great experiences that don't require their own app in order to function.

Indeed, playing games within the context of a messaging app is fundamentally different from downloading an app. This leads to a number of unique challenges and opportunities, which Blackstorm has sought to address in EverWing with a combination of technical knowhow and thoughtful design.

“We have to take what would typically be a very large downloadable on the app store and turn it into something that loads in a maximum of 10 to 20 seconds,” says Carter. “And then we need the UI and UX to be as frictionless as possible.”

He adds that Messenger boasts one billion monthly active users, which means Facebook Instant Games have to be equipped to handle a potentially huge player base.

“The very first thing that we have to recognise is that this is, from an onboarding standpoint, a very casual audience,” explains Carter. “They need to be able to understand the gameplay in the first 30 seconds.”

Considering Facebook Instant Games in context was also a priority for Blackstorm when designing EverWing, positioning the game as an augmentation of the chat and not a replacement activity.

To this end, it recently launched a co-op Boss Raid mode in EverWing - making it the first title on Facebook Instant Games to support synchronous co-op play.

“Cooperative multiplayer is not something we were able to include at launch because there was no way to reflect the names and profile pictures of the people you were playing with,” recalls Carter.

“The game didn't have access to that information because the API didn't exist yet."