This is how the game starts. If you have not entered your user id, you can't start the game. You can do this by tapping on the "Login" button. After that you can either start the game in story mode by clicking on the "Start" button or you can choose a specific level by tapping on "Select level". The highscore functionality will be activated in the next version. So you will be able to compete against your fellow students. In the "News" section you will get latest information about the app (e.g. updates).

Here you have to enter your user id. You can also optionally choose a nickname, which will be used in the next version to be displayed in the highscore list. After pressing the "Login" button you will return to the main menu and you can start the game.

Here will get information how to solve the level. Read this carefully since the game checks if you solved each task. Clicking on the "Start level" button leads you to the next screen.

In this screens you have to write Java code in order to define the behaviour of a specific tower. In some levels you also have to place the towers on the game grid via Java code. By clicking "Help" you will get additional information how to solve the level. The "Check" button allows you to proof analyze your code anytime if your code is correct (see next screen). If your code is correct, you can proceed by clicking the "Continue" button.

If your code has errors, you will get detailed information about it. When you think that your code is correct and the game did not do the check correctly, you will be able to send your code via email to project team anytime. If an error is detected in the level, a new level will be published immediately.

This screen provides additional help. Besides hints how to solve the current level, additional online resources for further reading are provided here.

This is the actual game screen. In some levels you can place towers by tapping on the game grid. In other levels, these towers are positioned via Java code. If the bugs reaching the finish and you have lost the game, you can restart it as often as you want.

After you have successfully solved a level you will be asked to rate this level. This helps us to improve new levels. You can proceed to the next level by tapping on the "Continue" button.