I've ported the old Tetris example (https://www.b4x.com/android/forum/threads/demo-cross-platform-tetris-clone.94146/#content) to X2 framework.
It is part of the examples pack.
This game is different than other games as there is nothing physical in this game.
Each "piece" is made of 4 blocks. Each block is a body by itself. There is always one moving piece.
The size of each block is 1 x 1 meters.
The world size is set in such way that the number of pixels (scaled pixels actually) per 1 meter is a whole number. This is important to avoid drawing issues.
The user input is checked every set interval (IntervalBetweenUserInputMs).
The bodies are moved in a non-physical way using SetTransform.
The main difference compared to the old example is that we don't need to manage the elements positions ourselves. It is done by the X2 framework.