1 - Stay alive. For this, when a line is full of blocks (color is not important), the line disappear providing you more time to prepare another line to remove.
2 - Reproduce "Pixel art" pattern with the color you want .
Every pattern made provides a lot of points but creates holes in the game that make it more difficult to stay alive...
you can rotate , move left or right some falling blocks but also : Hard drop and focus on the next falling block or Soft drop and still have the capacity to move left or right
you can also toggle color to help you perform the current pixel art challenge.
Most important is not velocity in this chill version of the game, most important is to use your neuron to choose the best moment in game to create pixel art. Pixel art creates holes on the board so it may not be wise to focus on art all the time...
Develop your own strategy to beat the worldwide best performance ! Good luck!