One of the most interesting challenges of creating games for a platform like the iPhone is figuring out a control scheme that really works. Ideally the controls should be completely natural to players so that the learning curve is as low as possible and players can spend more time playing, and less time learning.

The catch is that the iPhone is such a new platform there are no established standards for how to interact with the game. There is no thumbstick or arrow keys that people are used to using, and there's no A or B buttons to press.

While we have some good ideas on what might work well, we ultimately have to just test things out a bit and see what feels the best, and what just doesn't feel right at all. Today I'm going to talk about the basic player movement and next time I'll talk about trick execution.

Movement in a 3D game is actually pretty tricky since most people have issues (whether they want to admit it or not) in easily navigating and understanding 3D worlds. We knew that we wanted the movement to be accelerometer based but had to work to find something that was intuitive enough.

Our first attempt was an over the shoulder camera view. This actually worked out fairly well but it got a bit confusing as you came back into the pool and the camera flipped around quickly. You might think that you were going left but you ended up going right because of this.

Next we tried keeping the over the shoulder view but fixing the controls so that a tilt up on the phone always took you "North" in the pool and tilting left always took you "West", etc. We found that this worked great for experienced gamers, but got very confusing for casual players as you'd often times end up tilting left to go West, but moving right on the screen because of the direction you were traveling.

At this point we decided to drop the over the shoulder camera view for a bit and see if we could get a top down or isometric camera to work.

Our first top-down controls style was similar to the first over the shoulder one in that the camera followed the player around but always from a vantage point above and slightly to the side of the player. This again worked out great for experienced players but as the camera rotated around a bit became confusing to know which direction you wanted to go.

Our final test is what we've ultimately decided to use for the game and you can see in our Gameplay test video. We have an top-down camera view that follows the player around a bit but stays fixed to always be on the "South" side of the player. At the same time the tilt controls are also fixed so tilting up always goes North, Left is West, Right is East and Down is South. We've found this to work out very well and even new players are able to pick it up quickly.