Category «Android»

Why not a city-building game about quoting juridical text sources?

Wait, what? You heard right. With our latest project we had the wonderful challenge to fuse education with entertainment. 

So, what is CitApp about? Quoting texts and thoughts by others correctly is a necessity that aspiring lawyers will have to do quite often on their road of writing and analyzing. Especially the younger semesters devote a third of the evaluation of papers exclusively to errors in formalities. The rules of correct quotation are not hard to understand – but it’s something you might just muddle through somehow along the way, accepting point deductions or a failed exam even. *

Not anymore! Together with and for the team from the department of business law at the Martin-Luther University Halle we created a fun learning app that educates students in short lessons, workouts and a rewarding city builder all-in-one.

Citation as a city builder?

Before we came aboard, the project team – consisting of Marcus Bergmann, Ottmar Rentsch, Moritz Schwarz, Annabell Pfaff and Dieter Pfaff – conducted a well-prepared survey with about 230 of their students. In an exhausting amount of questions the team asked about learning and gaming habits including playtime, mobile games played, favorite scenarios and general player type. 

From there the team picked scenarios that would meet the requirement to motivate the students with an app that fit their habits: a game played in short segments, allowing a certain creativity and having a cozy scenario with city building elements.

Armed with this foundation and exercises for learning to quote text properly, the team looked for a game studio through an open bidding, which we as RAT KING took part in. Long story short, with our concept (based on the ideas by the project team) we won.

We did several educational games before, which are all playful and almost always have a range of player freedom while addressing complex topics like biodiversity, deforestation, climate change, people of the Bronze Age, or fake news. CitApp was therefore fascinating for us, as the two parts of the concept (quotation exercises and city building) don’t mix naturally at first glance.

A world dedicated to books

Honoring other authors’ thoughts and writings is the basis of the app, and an intention we completely embrace. The love for books and text – something we experienced especially through the mandatory book wall in Marcus’ office and his own book on the matter – we wanted to make visible through all of the game’s design. CitApp became a world dedicated to books. But the style of CitApp is only one of the elements to bring both worlds together.

In our game, the reward system for citation exercises and tutorials goes hand in hand with building your town. To collect money for your buildings you need to successfully master the exercises. To unlock new building types and rewards you need to prepare tutorials. The rewards let you expand your city and upgrade buildings.

The library is the central building and the place where the knowledge is based, where the tutorials are stored – a building that also has to be guarded against Plagiarists. Those little critters spice up the game even more: over time, Plagiarists and Bookworms will try to invade your city and need to be stopped by purchasing and strategically placing protection towers.

CitApp is the home of the Citlings (the citizens of your little empire) creating a welcoming atmosphere, where students can come back once in a while to a place of learning, next to challenges, fun and creativity.

How the footnote came into the app

While everything in game development is an interesting and often exciting journey, implementing the actual logic for the quotation exercises was especially tricky. Of course, some of them were easy to do – a simple quiz that tests your knowledge and memory is nothing new. But after this, the harder tasks are dynamically generated out of database entries, filled with dozens of details that can be part of a footnote. Author(s), noble title(s) of the author(s), editor(s), title, subtitle, source of information, place(s),... also included are informations that are superfluous, to give players an extra challenge in the higher levels. Not to forget the length of German juridical books like “Antrag zum zweiten Gesetz zum Schutz der Bevölkerung bei einer epidemischen Lage von nationaler Tragweite”. (There are longer ones.)

In any case we cannot just take the data out of the database and be done with it - it has to be processed and put in formulas (which had to be built from the ground up); and of course, several edge cases were identified during the development, which usually receive a special treatment in the code.

From the straight-forward exercise of sorting the elements of a footnote into the correct order, to the very complex  “find the error in an incorrect footnote”, where elements can both be missing or just wrong, designing and programming the learning exercises was highly demanding, and more so fulfilling when everything came together in the end. And this isn’t to say that the city-building part was any less interesting!

Working together

Creating so-called serious or educational games is never easy. A lot of them either fail to be entertaining or be actually educational. It is always challenging to find the right tone and gameplay to meet the target audience and their gaming habits to let the learning sink in naturally through gaming.

In the back from left: Ottmar Rentsch, Moritz Schwarz,
Friedrich Hanisch, Marcus Bergmann;
In the front from left: Annabell Pfaff, Jana Reinhardt

What we appreciated most about this project was how close we worked together with the university team and our testers to make sure the game does exactly that. Just to be clear: there are different learning types, games are not for everyone. Even the nicest and best-prepared tutorial found players who would rather read a book on the matter. But for those who need a little extra motivation it hopefully will become an app to fight plagiarism and procrastination.

* Ottmar Rensch, “Im Kampf gegen Plagiatoren und Bücherwürmer: Spiel-App lehrt Zitieren”,

The Sky of Bronze – The Game

As was promised in the last blog post, here’s a short article about the project we worked on in 2018 (mostly): a turn-based survival game as part of an app about the Nebra sky disk. The sky disk is a bronze circle with 30cm diameter and probably the oldest depiction of the known cosmos. It was found by treasure hunters in 1999, here in Saxony-Anhalt, and is now one of Germany’s most notable archeological discoveries.

The sky disk, as shown in the game

The project was an idea by MotionWorks, a local animation studio known for the Marco Polo series and games, and of course for a lot of other projects. MotionWorks’ plan was to create a mobile app that would teach children and teenagers about the sky disk in a playful manner: with short films, 360° pictures, puzzles, background information - and a game. So they approached us for a commission and we said yes, because educational games are satisfying to make, and because the regional and historical relevance of the topic appealed to us a lot - after all, the sky disk was found close to where we live and work.

As we only created the game and not the remaining parts of the app, we worked in parallel with other local businesses all under MotionWork’s lead. For example, codemacher was responsible for programming the app and making sure that people can use it on-site in Nebra via GPS. I.e., whenever you reach a certain hotspot in Nebra, a new animation would play. The Sisters of Design created the website and even a booklet with a comic, crafting instructions and an Android code for the app. It looks gorgeous and has a goat (the unofficial mascot of the whole endeavor) key ring pendant as a gimmick. MotionWorks themselves animated the clips and invented the story and characters: main characters are the two children Mimo and Leva who serve as guides through the whole app.

We created a game concept about village life and traditions a few thousand years ago, when the sky disk existed for quite some time already and was now worshipped and sacrificed. Thus our game does not really cover the disk (other than using a picture of it here and there), but the Unetice culture, which came around 1,000 years afterwards. This way, our game could reuse graphic assets from the rest of the app, as the animations followed a Unetice family trying to prevent their people’s demise.

Primary goal was writing a concept that would not be yet another color matching game, with bronze stars and moons in place of the jelly beans maybe. Instead we eventually envisioned a survival game on a small grid-based world, strongly inspired by board games, and this level would change constantly both through actions by the player (e.g. uncovering the board tiles, cutting trees, hunting animals) and by random events (e.g. forest fires, flooded lands). The player would walk around to gather resources like wood, meat and fur, and trade these against tools and - most importantly - bronze jewellery. Starting as a pauper, with this bronze players achieve higher and higher ranks: becoming the chieftain is the ultimate goal of the game. Such a high-score system was fitting, as hierarchical structures were established during the bronze age.

The hardest part of the game was to make the workload manageable. For example, we planned to have several mini games which would simulate the gathering of each resource. Only after creating a few prototypes for them it became clear that the amount of mini games had to be cut down to one. Instead of hunting animals with arrows in a “Angry Birds”-like fashion and similar gameplays, we settled for an abstract Minesweeper-inspired game that we could reskin for each activity (fishing, rabbit hunting, tree cutting, etc). Although this sounds like we betrayed our original goal, make no mistake: the mini games are only one part of the sky disk game. The player has to explore the world, plan their path, interact with various traders, sacrifice items to the gods, and so on - all before running out of time.

Just like in the app’s animated movies the protagonists are the Unetice children Mimo and Leva. The player plays one of them, and during the game, every few rounds a randomly chosen event happens. This was done via “collectible” cards featuring short stories describing the world and life back then. To some extent the cards also help to give the player a sense of progress, as they follow the four seasons over the span of one year - the game starts with spring and ends with winter.

Apart from being a cool project overall, it was nice that the app was showcased a bit more officially than usual. Because it has a regional impact (i.e. relevance to the region) it was funded by the county Saxony-Anhalt and by the Mitteldeutsche Medienförderung, and thus it was presented at the state chancellery in Magdeburg (the capital of our county) and later again at the Ark of Nebra. The Ark is a modern-looking museum serving as starting point for a walking tour to the look-out at the top of the ancient Holy Mountain - where the sky disk was dug out in 1999.

The Ark of Nebra

When the app was completed it was uploaded on Apple’s AppStore and Google’s PlayStore. We'd like to thank MotionWorks for the opportunity to work on this project - it was very interesting to learn about the sky disk after having seen it (or rather a copy of it) in the Landesmuseum already, and a joy to create something meaningful yet fun.

If you want to talk with us (and other enthusiasts) about our games and/or game development in general, visit us at our Discord!

Global Game Jam 2017 – Post Mortem

Global Game Jam 2017 - Hands Off Thief

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In January 2017 Jana and I were part of the Global Game Jam, as usual. We had some doubts we'd do it again in Leipzig, because every year it gets a bit harder to wake up in the HTWK (the university where the jam site is located) without a shower or hot water at all. Yes, we're getting older. Our plans went back and forth between not going at all, or driving back home for the nights, or getting an AirBnB. In the end we did it as always.

Thankfully! Commodations aside, it was a very nice experience. A few days before we made some key decision for our jam entry, especially the choice of target platform: VR. As we don't own a full-blown HTC Vive or so, we made a Google Cardboard game for Android. I think it turned out quite well, because it was doable in the scope we aimed for, even though it was our first VR game.

The theme itself ("Waves") wasn't very interesting, but it slowly formed the direction of our game. When we began to think in terms of sound waves, we soon decided that some radio in our game would tell the player what to do. So you'd be in some kind of labyrinth, trying to find that radio by searching around and listening to its noise, and then activate it, because it tells you how to reach the exit. This became less important later, but it's still in the game. So while we don't feature "waves" promintently, the game was definitely inspired by it.

One of the first WIP screenshots

What we have now is an atmospheric stealth game where you play some thief or treasure hunter in a haunted mansion. You walk around, steal things (mostly valuables), evade scary ghosts, use keys, and find the radio and the exit. As the game is a Virtual Reality game, the player's movement is restricted to gliding between square floor tiles in cardinal directions. This is very similar to my Ludum Dare entry Wood for the Trees from last year, but this time the limitation was imposed to us because of the nature of VR games. Free movement was out of question, and a typical "magically beam to place" approach could have been a bit too complex for our first 48 hours VR game. In the end, the limited movement also helped to define the simple but effective behaviour of the evil ghosts, which don't follow you but patrol between the rooms in the same manner as the player.

As usually our games have a somewhat high entry barrier, one of our goals was to simplify controls. With a VR game this seemed easy to do - you don't have much different input methods anyway. All you can do in our jam entry is looking around and take stuff by looking at it for a short time, which is why Jana had the idea to name it Hands Off Thief, as you steal without using your hands... Initially I planned to have the same approach for walking around the rooms - an arrow on the floor tells you if you're allowed to walk into that direction you're looking, and if so, looking at the arrow for a short time moves you to the next room. But it turned out that this is a bit awkward, as you'd always have to look down to walk around. Now players have to activate the trigger (i.e. touch the screen of their phone) when the arrow is shown, which feels a bit more natural.

I prepared by reading articles about VR development for mobile platforms. It was helpful to know that there are some heavy restrictions regarding drawcalls and polycount in order to maintain 60 frames per seconds on a phone. This way I wouldn't be surprised by bad performance at the end of the jam. Thus, from the beginning the Unity project was set up to use cheap vertex lighting, and I programmed a simple occlusion culling i.e. only the room you're in and adjacent rooms get rendered. We also tried to minimize the amount of different materials for everything.

The first thing we did when we started the development was trying to find out how big the virtual rooms should be. Several hours went into discussions if the walls are too near or too far away, if the ceiling is too low, or if the texture scale on the floor is okay. Probably not everything makes sense in the final game; some things were kept for the atmosphere. Especially the lighting was a bit of a headache, until we went with strong darkness and the player having a point light at their center. Every ghost has two lights - on for his current position, and one for the target position. This way, a player can predict if the ghost soon will be floating towards them. And from time to time a lightning strikes (even when there's no window), so there should be enough to see anyway.

Of course we had some help! When he wasn't sleeping Björn Grunewald created some 3D models like the loot, and my brother Ludwig 'KingLudi' Hanisch - as usual - agreed to compose the music. Ludwig was in another city, and when I sent him some screenshots it was very late, so I wasn't sure if he was still willing to do it. But he sent a nice track in time. Afterwards he wasn't content with it, as it didn't quite play along with the visuals. The problem was that Jana and I were late in defining the atmosphere and couldn't send him a meaningful video, so he only had the screenshots with bad lighting as reference. A few days later Ludwig sent us a new, much more eerie track which fit perfectly, and I updated the game. You can play this new and better version by downloading the APK on

Overall the Global Game Jam was cool; you might also want to have a look at the other games created at our site in Leipzig. By the way, one aspect I learned to dislike about the GGJ website is that you cannot edit your entry afterwards. I understand that they wouldn't want people to fake their entries, but it would be nice to be able to offer patches, or just add stuff you forgot.

We also might choose to register a jam site in our own city next year, because we found some potential co-jammers!

> Try Hands Off Thief here! <