Google In-App Payments: Convenient for buyers and developers

Todd and I are always looking for good ways to monetize our web games so we can continue doing what we love: making more games! With Entanglement, we created extended content that players can purchase if they really enjoy the game, and with our latest creation, Thwack!!, we created a reward system using tokens that can be won by playing the game or purchased for a few cents.

Back in January when we first released our Sakura Grove Expansion for Entanglement, we implemented an email and key system for purchasing: to access the expansion set for the first time, a player would make the purchase, wait for the confirmation email to arrive, and follow the instructions to get back into Entanglement with the key to unlock their purchase. Not only was the process indirect and inconvenient for purchasing a digital good, but it also took us quite a bit of time to develop and debug.

In developing our latest game, Thwack!!, we decided to implement Google In-App Payments. In-app payments are ideal for selling digital goods and the small 5% transaction fee is wonderful for the small transactions common to games.

Once our game's store interface was set up, I was pleasantly surprised to find integrating in-app payments very quick and straight-forward. In fact, I first began reading the documentation early one morning, and by following the very concise step-by-step instructions I had in-app payments implemented in Thwack!! by lunch time!

We were quite pleased with both the appearance and implementation for Thwack!! so converting Entanglement’s purchase process to Google In-App Payments was a natural next step. However, setting up in-app payments for two separate games on one seller account highlighted something I would need to change with my initially simplistic Thwack!! integration, where I had implemented the entire process, including the postback URL, through the web game itself.

Since I was adding a second game on the same seller account, I had to separate the postback process from Thwack!!. After a bit of restructuring, and less than a day’s work, I had In-App Payments running in both Thwack!! and Entanglement with a separate service that tracks orders apart from the games as shown below.

We now have Google In-App Payments running in both games in less than two days’ worth of programming with the additional benefit of a separate central location to track orders.

We found that Google In-App Payments is not only convenient for our game players by allowing them to remain in the game experience while making their purchase, it is also convenient for us as game developers by making the integration process quick and easy to implement.

HTML5 AppCache and Keeping Clients Updated

If you've played Entanglement or Thwack!!, you may notice that it takes a while to load the first time. Fortunately, if you've installed Entanglement as a web app, or played Thwack!! more than once, you may have also noticed that subsequent visits require much less time to load. This is thanks to the HTML5 application cache.

The application cache (or "appcache" for short) allows us to store the game and all of its audio and graphics files locally on your computer (here's a nice tutorial on implementing an appcache). Next time you play the game, the application cache loads the files from your computer rather than pull them from the Internet. The beauty of this is two-fold. First, the game can start loading quickly since it doesn't need to check for anything online first. Second, the game can load without a connection to the Internet at all!

One drawback to this is that if someone plays the game and then returns some time later, the next time they play the game their browser loads a version of the game that's potentially weeks or even months old. If there's an updated version, appcache will load the files in the background to prepare for the next time the game is loaded, but the version the player is currently experiencing is the old version until they reload the page. This isn't too much of a problem with Entanglement where changes from one version of Entanglement to another do not negatively effect the experience.

What a player sees if running an old version

However, with the online multiplayer aspect of Thwack!! it's a bit more disruptive. With Thwack!!, each client independently calculates the results of a given turn, and those results have to match up with each other. For instance (not connected to reality... ...okay maybe a little), if Todd decides on a whim to change all of the discs' sizes, weights, and damping, the new version he deploys will calculate a different result for a turn than an older version stored in appcache. This effectively breaks the experience for not only the player whose browser loaded an old version of Thwack!! but also all of the players connected to that particular game.

The fix is fortunately quite simple. When a new version has loaded in the background, we know that we're not running the latest version. We can check this by implementing the following event listener:

var newVersionWaiting = false;
var updateReady = function()
{
    newVersionWaiting = true;
};

window.applicationCache.addEventListener('updateready', updateReady, false);

Now that we're aware of a new version waiting on the sideline, we can notify the player that they're running an outdated version before we let them in on a multiplayer game. Additionally, we attach a page refresh call to the message dialog's "OK" button to make it even easier for them to get the most updated version. Here's a snippet from Thwack!! where "messageBox" creates the dialog you see in the screenshot above. The first parameter is the message and second parameter, a function, is executed by clicking "OK":

if(newVersionWaiting)
{
    messageBox(RELOAD_THWACK, function(){window.location.reload();});
}

Edison Project Win!

A few weeks ago I mentioned we were one of 9 contenders in a local business competition called the Edison Project. We achieved second place! It was a tough competition, but we lauded the virtues of HTML5 and threw in a bunch of games to give us an edge.

Thanks to: Danny Hearn and the Catawba Chamber for putting this competition together; the sponsors: Alex Lee, CenturyLink, CVCC, Catawba County Government, and the Committee of 100 for making it a reality; and Bill Parrish of the SBTDC who worked with us and gave us invaluable feedback as we put together our business plan and presentations!

Todd's response to seeing a check this large for the first time.

We also want to congratulate the first place winner, David Washco, with Price Drive. He doesn't have his product out yet, but he has a very compelling idea that we hope to see come to life soon. The third place winner, Peter Lohr, with Advanced Hydrogen Technologies Corporation, also has a brilliant idea that could fundamentally change car fuel systems.

Until the official news release gets out, hopefully this picture of Todd will suffice to show our excitement in the recognized feasibility of our business plan... ...and winning a check that's taller than my sons.

Update: Hickory Daily Record article