When creating a game, the in-game store or shop is one of the most critical parts of it. It is the part that has the tendency to be the least fun for the user but is the most crucial for the developer. Without a shop, most in-app purchases won’t happen in your game. This is why, even though it may not be fun, a developer should pay close attention when building up his shop. For our upcoming game, Tumble Panda, we put some effort and time into our shop and went through some iterations. With this game as an example, I want to show you how you can build a nice store.

 Step 1: Identify your store’s criteria

First, you might want to identify critical criteria for your game’s store. As for us, we worked out the following points. Now, as I’m a lover of simplicity and like having one screen doing one thing, I like to also have a more minimalistic design, for example with rather big instead of many buttons. Of course, this criteria may vary from individual preferences and from game to game: Our biggest point was that it should be easy and seamless to use. This is a very soft formulation, so soft, that it is probably a criteria for every app ever specified. This is why, from this starting point, we worked out six other, more specific points:

1. The design should fit the rest of the game.
2. The design should be as minimalistic as possible while still highlighting the different functionalities of the virtual goods.
3. Animations should be as quiet as possible.
4. There should be little  enough goods to not confuse the user while still providing enough variety to make purchases attractive.
5. The flow from overview to purchase should be done with as little clicks as possible.
6. There should be possibilities to gain in-game currency without having to pay “real” money.

Furthermore, in order to keep it easy for us, and since we would need to experiment a bit to create a balanced variety of goods, we wanted to have the content easy to configure.

Step 2: Implement

Once the soft and hard criteria for your game are done, you should start implementing according to them. You will probably go through some iterations in which you will experiment, test and refine your shop more and more. Usually there area many ideas in the beginning, so it is probably the easiest to simply start implementing analog by sketching your shop and its transitions first. Here is how this looked in our case:

From the number of screens, your store will probably look somewhat similar. A screen to purchase items and a screen for purchasing your in-game currency with “real” money are the vital parts of it. Then it is time to test and try out.

First, we thought about a simplistic design that would show all the items we offer represented by icons. Once the user clicked on one of these items, he would be taken to the next step of the shopping procedure in which he would see the item’s details, like description and price, a bigger image of the item and confirm and cancel buttons.

Steps 3, 4 and 5: Iterate

When testing this approach, we found that the initial display of small  icons for all the items and details to them on click was simple, but only on the first view. Because for the user to find out about the different items, he would need to click on each, read through the description and then click on the next item. We had a trade-off between a simplistic design and a simplistic user interaction path.

This was the reason why we decided to go with a design that displays more information, which can be positive but also negative. We decided to put our items in two categories which can be accessed by tabs. For the item’s representation, we chose lists:

This changes are the reason why it is important for you to chose a method in which you can quickly test rough concepts and ideas, like just sketching them first, then implementing a basic version and putting the final finish only in the end. This way, major changes will be less pricy when they appear on  this stage. Imagine you implement your complete store and then realize you sticked to the wrong concept and need to implement the whole UI interaction again.

You need to as well talk to your users and have your different ideas tested. Then implement changes, based on your user’s feedback. In our case, the testing team consists of a mixture of employees, friends and relatives which span from the age of 7 to 52. This test-team should be not too big and fast in making responses so that you can really have a process of showing your work, receiving immediate feedback, improving upon this feedback, and showing your work again.

Once you decided on the basic way your store’s design and interaction  works, it’s time to go over the smaller parts. It should be a set of iterations with continuous improvements, followed by tests, followed by the next iteration.

Here is an overview over the various iterations we took on our store. As you can see, we sometimes only did small graphical changes, trying to improve more and more. Then, in the end, we gave it the final touch and it is now in the state in which it will go into the beta testing phase.

 

Step 6: Balance your content

When you look closely to the changes we made, you may notice that not only the graphics changed, but also the content of the store. In the process of development we found out, that some of the items we thought would be good to have in our store weren’t but others were.

The items in a store should be useful and affordable enough to make some of them easy to purchase, but not cheap enough to buy through the game without making real money purchases. The prices of your store and your virtual currency determine the value you give to the user’s time. If you for example give up to 50 gold coins for a level for which the user needs 2 minutes to play and offer 1000 gold for $0.99, that would give the users time a value of $0.02475 per minute. Obviously this value shouldn’t be too high nor insultingly low.

Furthermore, the items in your store should provide some use to the user. In our case, we created two categories for Tumble Panda, items that are consumable and which can be used once and need to be re-purchased, and items that improve the protagonist’s power gradually and stay forever.

To balance your content well, I recommend to do some more iterations with your Alpha-testers, track their behavior, for example with Flurry (we use this one) or Google Analytics, and ask them for more feedback.

Summary

In the end I hope we met all the criteria we specified. Some things may still need adjustment, but the beta phase will show.

Besides a clear set of criteria to measure against, consecutive iterations with a set of testers involved are crucial to creating the store that not only you but also your users love. Personally, I also like to break the content down to the essential elements with every screen being responsible for exactly one thing, while keeping buttons and touch areas big, since the store is designed for a mobile device. The store of Temple Run for example really appeals to me, since it has all the stuff in one place, while items are still clearly grouped using separators and the user does not need many clicks to purchase an item.

I’m interested in unconventional and great ways of implementing stores and monetization systems. If you know any, please feel invited to share in the comments.

P.S.: We are looking for beta testers for Tumble panda. If you want to join, please let me know.