First, you can use this link to play the game itself without any site overlay: https://game299716.konggames.com/gamez/0029/9716/live/index.html

To manually move between levels for practice, you can open the console (in the developer tools, press F12), and then type:

game=cr_getC2Runtime();game.doChangeLayout(game.layouts_by_index[0]);

While changing the number in the brackets to the relevant number: 0 - Move to the title screen 3 to 14 - Move to levels 1 to 12, respectively

If you move between levels in this way, it is recommended to move first to the title screen and then move to the new level, because those manual transitions don't reset the levels music.

Extra screens: 1 and 2 - screens of a test level with nothing to do 15 to 18 - The screens of the cutscene at the end of the game 19 - An interesting test variation of the tutorial level, but harder 20 - Unused prototype of a level select screen