int x_figure = 0;
int y_figure = 0;
int level = 26;

void setup()
{
size(650,650); 
}

void draw()
{
fill(int(random(255)),int(random(255)),int(random(255)));
for (int i = 0; i < 650; i+=25)
{
rect(x_figure+i,y_figure,25,25);
}
y_figure+=25;

if (y_figure == level*25) 
{
background(125,125,125);
fill(255,0,0);
rect(0,level*25,650,25);
level--;
y_figure=0;
}

if (level == 0) level = 26;
delay(25);

}