diff --git a/wled00/FX.cpp b/wled00/FX.cpp
index 27bd730d..786ea692 100644
--- a/wled00/FX.cpp
+++ b/wled00/FX.cpp
@@ -1001,14 +1001,6 @@ uint16_t WS2812FX::mode_running_color(void) {
   return running(SEGCOLOR(0), SEGCOLOR(1));
 }
 
-
-/*
- * Alternating red/green pixels running.
- */
-uint16_t WS2812FX::mode_merry_christmas(void) {
-  return running(RED, GREEN);
-}
-
 /*
  * Alternating red/white pixels running.
  */
@@ -1991,7 +1983,7 @@ uint16_t WS2812FX::mode_colortwinkle()
   if (!SEGENV.allocateData(dataSize)) return mode_static(); //allocation failed
   
   CRGB fastled_col, prev;
-  fract8 fadeUpAmount = 8 + (SEGMENT.speed/4), fadeDownAmount = 5 + (SEGMENT.speed/7);
+  fract8 fadeUpAmount = _brightness>28 ? 8 + (SEGMENT.speed>>2) : 68-_brightness, fadeDownAmount = _brightness>28 ? 8 + (SEGMENT.speed>>3) : 68-_brightness;
   for (uint16_t i = 0; i < SEGLEN; i++) {
     fastled_col = col_to_crgb(getPixelColor(i));
     prev = fastled_col;
@@ -3144,6 +3136,59 @@ uint16_t WS2812FX::mode_drip(void)
 }
 
 
+/*
+ * Tetris or Stacking (falling bricks) Effect
+ * by Blaz Kristan (https://github.com/blazoncek, https://blaz.at/home)
+ */
+typedef struct Tetris {
+  float    pos;
+  float    speed;
+  uint32_t col;
+} tetris;
+
+uint16_t WS2812FX::mode_tetrix(void) {
+
+  uint16_t dataSize = sizeof(tetris);
+  if (!SEGENV.allocateData(dataSize)) return mode_static(); //allocation failed
+  Tetris* drop = reinterpret_cast<Tetris*>(SEGENV.data);
+
+  // initialize dropping on first call or segment full
+  if (SEGENV.call == 0 || SEGENV.aux1 >= SEGLEN) {
+    SEGENV.aux1 = 0;                            // reset brick stack size
+    SEGENV.step = 0;
+    fill(SEGCOLOR(1));
+    return 250;  // short wait
+  }
+  
+  if (SEGENV.step == 0) {             //init
+    drop->speed = 0.0238 * (SEGMENT.speed ? (SEGMENT.speed>>3)+1 : random8(6,40)); // set speed
+    drop->pos   = SEGLEN-1;           // start at end of segment
+    drop->col   = color_from_palette(random8(0,15)<<4,false,false,0);     // limit color choices so there is enough HUE gap
+    SEGENV.step = 1;                  // drop state (0 init, 1 forming, 2 falling)
+    SEGENV.aux0 = (SEGMENT.intensity ? (SEGMENT.intensity>>5)+1 : random8(1,5)) * (1+(SEGLEN>>6));  // size of brick
+  }
+  
+  if (SEGENV.step == 1) {             // forming
+    if (random8()>>6) {               // random drop
+      SEGENV.step = 2;                // fall
+    }
+  }
+
+  if (SEGENV.step > 1) {              // falling
+    if (drop->pos > SEGENV.aux1) {    // fall until top of stack
+      drop->pos -= drop->speed;       // may add gravity as: speed += gravity
+      if (int(drop->pos) < SEGENV.aux1) drop->pos = SEGENV.aux1;
+      for (uint16_t i=int(drop->pos); i<SEGLEN; i++) setPixelColor(i,i<int(drop->pos)+SEGENV.aux0 ? drop->col : SEGCOLOR(1));
+    } else {                          // we hit bottom
+      SEGENV.step = 0;                // go back to init
+      SEGENV.aux1 += SEGENV.aux0;     // increase the stack size
+      if (SEGENV.aux1 >= SEGLEN) return 1000;   // wait for a second
+    }
+  }
+  return FRAMETIME;  
+}
+
+
 /*
 / Plasma Effect
 / adapted from https://github.com/atuline/FastLED-Demos/blob/master/plasma/plasma.ino
diff --git a/wled00/FX.h b/wled00/FX.h
index 27329a0a..44c57d07 100644
--- a/wled00/FX.h
+++ b/wled00/FX.h
@@ -164,7 +164,7 @@
 #define FX_MODE_COMET                   41
 #define FX_MODE_FIREWORKS               42
 #define FX_MODE_RAIN                    43
-#define FX_MODE_MERRY_CHRISTMAS         44
+#define FX_MODE_TETRIX                  44
 #define FX_MODE_FIRE_FLICKER            45
 #define FX_MODE_GRADIENT                46
 #define FX_MODE_LOADING                 47
@@ -501,7 +501,7 @@ class WS2812FX {
       _mode[FX_MODE_COMET]                   = &WS2812FX::mode_comet;
       _mode[FX_MODE_FIREWORKS]               = &WS2812FX::mode_fireworks;
       _mode[FX_MODE_RAIN]                    = &WS2812FX::mode_rain;
-      _mode[FX_MODE_MERRY_CHRISTMAS]         = &WS2812FX::mode_merry_christmas;
+      _mode[FX_MODE_TETRIX]                  = &WS2812FX::mode_tetrix;
       _mode[FX_MODE_FIRE_FLICKER]            = &WS2812FX::mode_fire_flicker;
       _mode[FX_MODE_GRADIENT]                = &WS2812FX::mode_gradient;
       _mode[FX_MODE_LOADING]                 = &WS2812FX::mode_loading;
@@ -717,7 +717,7 @@ class WS2812FX {
       mode_comet(void),
       mode_fireworks(void),
       mode_rain(void),
-      mode_merry_christmas(void),
+      mode_tetrix(void),
       mode_halloween(void),
       mode_fire_flicker(void),
       mode_gradient(void),
@@ -884,7 +884,7 @@ const char JSON_mode_names[] PROGMEM = R"=====([
 "Scan","Scan Dual","Fade","Theater","Theater Rainbow","Running","Saw","Twinkle","Dissolve","Dissolve Rnd",
 "Sparkle","Sparkle Dark","Sparkle+","Strobe","Strobe Rainbow","Strobe Mega","Blink Rainbow","Android","Chase","Chase Random",
 "Chase Rainbow","Chase Flash","Chase Flash Rnd","Rainbow Runner","Colorful","Traffic Light","Sweep Random","Running 2","Aurora","Stream",
-"Scanner","Lighthouse","Fireworks","Rain","Merry Christmas","Fire Flicker","Gradient","Loading","Police","Police All",
+"Scanner","Lighthouse","Fireworks","Rain","Tetrix","Fire Flicker","Gradient","Loading","Police","Police All",
 "Two Dots","Two Areas","Circus","Halloween","Tri Chase","Tri Wipe","Tri Fade","Lightning","ICU","Multi Comet",
 "Scanner Dual","Stream 2","Oscillate","Pride 2015","Juggle","Palette","Fire 2012","Colorwaves","Bpm","Fill Noise",
 "Noise 1","Noise 2","Noise 3","Noise 4","Colortwinkles","Lake","Meteor","Meteor Smooth","Railway","Ripple",