Rocket Riot Ignite Presentation

Following the example set by Niels, here are the slides for my Ignite presentation at Mediamatic on 27 January 2011. The presentation was limited to 5 minutes, with exactly 15 seconds per slide.

*silence while the audience basks in the glory of Rocket Riot*

So this is a game we made. It's called Rocket Riot and it's a side scrolling dual stick shooter for Xbox LIVE Arcade.

Recently we've ported Rocket Riot to the Windows Phone 7. This talk will focus on one of the interesting aspects of that process, which is adapting the dual stick control scheme to the phone's touchscreen. I know I don't have a lot of time so I'll try to keep this short.

It all started in 1982 when Robotron revolutionized the Arcade with its innovative controls: instead of a single joystick it used two. The left joystick was used to move the player around the screen while the right allowed 8-directional firing, independent of movement.

Recently the dual stick shooter genre has become very popular. This is a result of modern controllers coming equipped with two joysticks and the rise of cheap downloadable titles with arcadey gameplay. Rocket Riot is one of those downloadable dual stick arcade games but its controls are a little different than most.

Movement in Rocket Riot is not a simple matter of aiming and moving. It is more comparable to Lunar Lander. If the player holds the stick in a neutral position his character will plummet to the ground. Move the joystick forward to engage the jetpack, causing the character to fly upwards. Maintaining a steady altitude can be a delicate affair.

Shooting is similarly nonstandard. The player points the joystick in a direction to aim. He then holds it there to charge the bazooka. When it is fully charged the player lets go, causing the joystick to snap back and the character to fire his rocket. This feels similar to shooting a rubber band with your fingers.

A great deal of the skill in Rocket Riot comes from mastering these controls. When porting it to the Windows Phone we had to find a way to make them work on a touchscreen. The solution that a lot of games use is to offer a virtual joystick. The game simply denotes an area of the screen as the joystick and tapping on it moves the character.

This is what Rocket Riot looks like with virtual joysticks. An obvious downside is that the two circles take up a lot of screen space. There are worse problems with this setup though: we found that the game was nearly unplayable. Our thick thumbs couldn't muster the precision required by the flight controls and shooting without the physical click-back of releasing the joystick felt lackluster.

So we had to make some tough decisions. After some deliberation we decided to bite the bullet and throw away our beloved control scheme in favor of playability.

Gravity went out the window. On the Windows Phone, characters simply move in the direction indicated by the joystick and hover in place automatically.

The shooting system was also removed and replaced by a simple yet very intuitive "swipe to shoot" mechanic. Just swipe your finger and the character will fire in that general direction.

With these changes the game was a lot better, but there was still the issue of the obstructing joystick graphic. We tried removing it but that made it very easy to lose track of its position.

What we wanted was a smart joystick that knew exactly what the user was trying to do. Maybe by reading his mind?

This is our first attempt at a smarter joystick. To combat the problem of losing the joystick we moved it to the user's finger whenever he pressed the screen.

This system works really well. It only works well, however, if you know exactly how it works. The invisible teleporting joystick proved very confusing without detailed explanation.

So we had to improve on it. This is our second attempt: a joystick that doesn't center itself on the player's tap position but rather moves towards it. The feeling is similar to placing a regular controller on the table and dragging it around by the stick.

And here is what people have said about it. I've taken the first page of comments from the app's reviews page and copied all of them that mentioned the controls. These are the positive results, with a few "surprisingly good" comments, which is illustrative for the current state of virtual joystickery.

Here are the negative comments from that batch. I'm not sure if MonkeyPants555's review should be classified as positive or negative. ContortedPuppy obviously prefers the original controls.

And as a final thought, here is something that we completely missed but a lot of users complained about: if a player gets too excited by our swipe controls he might accidentally hit the windows button which boots him back to the main menu without confirmation. Our test phones had different buttons so we didn't notice this at all during testing (protip: hold your phone upside-down to avoid this!).