From the intro to the game: "Test does not support mobile devices. It is very easy to miss with finger. We are working on new version of tests with better mobi

From the intro to the game: "Test does not support mobile devices. It is very easy to miss with finger. We are working on new version of tests with better mobile devices support, new problems to solve etc. However, it is not implemented yet." Since you have to select the bug in the code with the mouse, it's unusable on touchscreen mobile devices.