diff --git a/test-projects/fragments/cartridge/program.pbx b/test-projects/fragments/cartridge/program.pbx
index 94fd28b8..544f7917 100644
Binary files a/test-projects/fragments/cartridge/program.pbx and b/test-projects/fragments/cartridge/program.pbx differ
diff --git a/test-projects/fragments/src/main.pbs b/test-projects/fragments/src/main.pbs
index d81851a6..e8f1dcb6 100644
--- a/test-projects/fragments/src/main.pbs
+++ b/test-projects/fragments/src/main.pbs
@@ -4,7 +4,7 @@ import { Gfx } from @sdk:gfx;
 declare global ticks: int = 0;
 declare const SCREEN_W: int = 320;
 declare const SCREEN_H: int = 180;
-declare const CELL: int = 8;
+declare const CELL: int = 4;
 
 [Init]
 fn init() -> void
@@ -12,25 +12,80 @@ fn init() -> void
     ticks = 0;
 }
 
+fn abs_i(v: int) -> int
+{
+    if (v < 0) {
+        return 0 - v;
+    }
+    return v;
+}
+
 [Frame]
 fn frame() -> void
 {
     ticks += 1;
-    for y: int from 0 until SCREEN_H step CELL {
-        let gy = y / CELL;
-        for x: int from 0 until SCREEN_W step CELL {
-            let gx = x / CELL;
-            let wave_a = (gx * 211 + ticks * 9) % 31;
-            let wave_b = (gy * 173 + ticks * 7) % 63;
-            let wave_c = ((gx + gy) * 149 + ticks * 11) % 31;
-            let wave_d = ((gx * gy) + ticks * 5) % 63;
+    let cx = SCREEN_W / 2;
+    let cy = SCREEN_H / 2;
+    let phase = ticks / 2;
 
-            let r = (wave_a + wave_c) % 31;
-            let g = (wave_b + wave_d) % 63;
-            let b = ((wave_a + wave_b + wave_c) / 3) % 31;
+    Gfx.clear(new Color(0));
+
+    for y: int from 0 until SCREEN_H step CELL {
+        let dy = y - cy;
+        for x: int from 0 until SCREEN_W step CELL {
+            let dx = x - cx;
+            let seed_x = dx / 3 + ((phase % 29) - 14);
+            let seed_y = dy / 3 + (((phase * 3) % 23) - 11);
+
+            let zx: int = seed_x;
+            let zy: int = seed_y;
+            let iter: int = 0;
+
+            while iter < 5 {
+                let ax = abs_i(zx);
+                let ay = abs_i(zy);
+                let nx = ((zx * zx - zy * zy) / 48) + seed_x + ((ay * 3) / 8) - 9;
+                let ny = ((ax * zy) / 24) + seed_y + ((phase + iter * 7) % 17) - 8;
+                zx = nx;
+                zy = ny;
+                iter += 1;
+            }
+
+            let axf = abs_i(zx);
+            let ayf = abs_i(zy);
+            let energy = (axf + ayf + iter * 9 + ((x + y + phase) % 31)) % 128;
+
+            let r = if energy > 95 {
+                24 + ((phase + x / CELL) % 7)
+            } else if energy > 63 {
+                10 + ((energy + phase) % 12)
+            } else {
+                (energy / 8) % 8
+            };
+
+            let g = if energy > 95 {
+                8 + ((phase + y / CELL) % 22)
+            } else if energy > 63 {
+                14 + ((energy + phase) % 26)
+            } else {
+                2 + ((energy / 4) % 10)
+            };
+
+            let b = if energy > 95 {
+                26 + ((phase + x / CELL + y / CELL) % 5)
+            } else if energy > 63 {
+                16 + ((energy + phase) % 14)
+            } else {
+                6 + ((energy / 3) % 16)
+            };
 
             let color_raw = r * 2048 + g * 32 + b;
             Gfx.fill_rect(x, y, CELL, CELL, new Color(color_raw));
         }
     }
+
+    Gfx.draw_circle(cx, cy, 24 + (phase % 6), new Color(31743));
+    Gfx.draw_circle(cx, cy, 52 + ((phase + 3) % 9), new Color(21119));
+    Gfx.draw_circle(cx, cy, 78 + ((phase + 5) % 7), new Color(10591));
 }
+// Estimated frame cost: 3600 fills + ~18000 fractal-iteration steps + 3 circles/frame at CELL=4.