1. Launch the game "Draw Blocks 3D" on your mobile device.

2. Observe the grid filled with various squares and empty gaps that need to be filled.

3. Your goal is to draw shapes that form 3D cubes to fit perfectly into the empty spaces.

4. Use your finger to draw directly on the screen. Trace the outline of the cube shape you believe matches the gap.

5. Precision matters—make sure the shape you draw corresponds to the size and orientation of the gap.

6. After drawing, the game will automatically convert your drawing into a solid 3D cube.

7. If your cube fits correctly into the gap, it will snap into place and the board will update.

8. Successfully filling all the required gaps will complete the level and move you to the next one.

9. Be mindful of the timer displayed on the screen. You have a limited amount of time to draw the correct cube.

10. As you progress through levels, the puzzle complexity and number of gaps will increase, requiring quick thinking and accurate drawing.

11. If you make a mistake, you can try again within the time limit.

12. Continue drawing and solving puzzles to complete levels and improve your score.