diff --git a/.gitignore b/.gitignore
index 37a89c0..c8702eb 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,6 @@
 .cache
 compile_commands.json
-main
+no_dod
 *.png
 raylib
 raylib-build
diff --git a/Makefile b/Makefile
index 52e0d16..a633a25 100644
--- a/Makefile
+++ b/Makefile
@@ -2,12 +2,11 @@ BUILD_TYPE = debug
 CC         = clang
 CFLAGS     = -Iraylib/include -Iwapp/src
 LDFLAGS    = '-Wl,-rpath,$$ORIGIN/raylib/lib' -Lraylib/lib -lraylib
-OUT        = main
 
 ifeq ($(BUILD_TYPE),debug)
 	CFLAGS += -g
 else
-	CFLAGS += -O2
+	CFLAGS += -O2 -DNDEBUG
 endif
 
 .PHONY: all raylib game
@@ -21,4 +20,4 @@ raylib:
 
 game: raylib
 	cd wapp && python3 -m codegen
-	$(CC) $(CFLAGS) $(LDFLAGS) main.c wapp/src/wapp.c -o $(OUT)
+	$(CC) $(CFLAGS) $(LDFLAGS) no_dod.c wapp/src/wapp.c -o no_dod
diff --git a/main.c b/main.c
deleted file mode 100644
index f16acd1..0000000
--- a/main.c
+++ /dev/null
@@ -1,134 +0,0 @@
-#include "wapp.h"
-#include "raylib.h"
-#include <stdint.h>
-#include <assert.h>
-
-#define WIDTH 1280
-#define HEIGHT 720
-#define HALF_WIDTH (WIDTH * 0.5f)
-#define HALF_HEIGHT (HEIGHT * 0.5f)
-#define MAX_OBJ_DIM 30
-#define MIN_OBJ_DIM 15
-#define BG_COLOR (Color){.r = 0xea, .g = 0xf2, .b = 0xe3, .a = 0xff}
-#define FG_COLOR (Color){.r = 0x42, .g = 0x4C, .b = 0x55, .a = 0xff}
-#define OBJECT_COUNT 10
-#define MSG_BUF_LEN 4096
-#define abs(A) (A < 0 ? A * -1 : A)
-#define min(A, B) (A < B ? A : B)
-#define max(A, B) (A > B ? A : B)
-
-#define OBJECT_COMMON struct {Position position; Scale scale;}
-
-typedef struct Position Position;
-struct Position {
-  f32 x;
-  f32 y;
-};
-
-typedef struct Scale Scale;
-struct Scale {
-  f32 width;
-  f32 height;
-};
-
-typedef struct Velocity Velocity;
-struct Velocity {
-  f32 x;
-  f32 y;
-};
-
-typedef struct Wanderer Wanderer;
-struct Wanderer {
-  OBJECT_COMMON;
-  Velocity velocity;
-};
-
-typedef struct SlowZone SlowZone;
-struct SlowZone {
-  OBJECT_COMMON;
-};
-
-void init_wanderer(Wanderer *wanderer, XOR256State *state);
-void move_wanderer(Wanderer *wanderer);
-f32 get_random_float(XOR256State *state);
-
-int main(void) {
-  InitWindow(WIDTH, HEIGHT, "DOD test");
-  SetTargetFPS(120);
-
-  Allocator arena   = wapp_mem_arena_allocator_init(MB(10));
-  XOR256State state = wapp_prng_xorshift_init_state();
-  Wanderer *objects   = wapp_mem_allocator_alloc(&arena, sizeof(Wanderer) * OBJECT_COUNT);
-  assert(objects != NULL);
-
-  for (u64 i = 0; i < OBJECT_COUNT; ++i) {
-    Wanderer *object = &(objects[i]);
-    init_wanderer(object, &state);
-  }
-
-  while (!WindowShouldClose()) {
-    for (u64 i = 0; i < OBJECT_COUNT; ++i) {
-      Wanderer *object = &(objects[i]);
-      move_wanderer(object);
-    }
-
-    BeginDrawing();
-
-    ClearBackground(BG_COLOR);
-
-    for (u64 i = 0; i < OBJECT_COUNT; ++i) {
-      Wanderer *object = &(objects[i]);
-      DrawRectangle(
-          (i32)object->position.x,
-          (i32)object->position.y,
-          (i32)object->scale.width,
-          (i32)object->scale.height,
-          FG_COLOR
-      );
-    }
-
-    EndDrawing();
-  }
-
-  wapp_mem_arena_allocator_destroy(&arena);
-
-  CloseWindow();
-
-  return 0;
-}
-
-void init_wanderer(Wanderer *wanderer, XOR256State *state) {
-  wanderer->position = (Position){
-    .x = wapp_prng_xorshift_256(state) % WIDTH,
-    .y = wapp_prng_xorshift_256(state) % HEIGHT,
-  };
-
-  f32 scale = (f32)((wapp_prng_xorshift_256(state) % (MAX_OBJ_DIM + 1 - MIN_OBJ_DIM)) + MIN_OBJ_DIM);
-  wanderer->scale = (Scale){
-    .width  = scale,
-    .height = scale,
-  };
-
-  wanderer->velocity = (Velocity){
-    .x = get_random_float(state),
-    // .y = get_random_float(state),
-    .y = 0.0f,
-  };
-}
-
-void move_wanderer(Wanderer *wanderer) {
-  wanderer->position.x += wanderer->velocity.x;
-  wanderer->position.y += wanderer->velocity.y;
-
-  if (wanderer->position.x > WIDTH ||
-      wanderer->position.x + wanderer->scale.width < 0 ||
-      wanderer->position.y > HEIGHT ||
-      wanderer->position.y + wanderer->scale.height < 0
-  ) {
-  }
-}
-
-f32 get_random_float(XOR256State *state) {
-  i64 random = (i64)wapp_prng_xorshift_256(state) - INT64_MAX;
-  return (f32)(random) / (f32)(INT64_MAX);
-}
diff --git a/no_dod.c b/no_dod.c
new file mode 100644
index 0000000..106258a
--- /dev/null
+++ b/no_dod.c
@@ -0,0 +1,222 @@
+#include "wapp.h"
+#include "raylib.h"
+#include <stdint.h>
+#include <stdbool.h>
+#include <assert.h>
+
+#define WIDTH 1280
+#define HEIGHT 720
+#define HALF_WIDTH (WIDTH * 0.5f)
+#define HALF_HEIGHT (HEIGHT * 0.5f)
+#define MAX_WANDERER_DIM 8
+#define MIN_WANDERER_DIM 3
+#define MIN_ZONE_DIM 30
+#define BG_COLOR (Color){.r = 0xea, .g = 0xf2, .b = 0xe3, .a = 0xff}
+#define FG_COLOR (Color){.r = 0x42, .g = 0x4C, .b = 0x55, .a = 0xff}
+#define ZONE_COLOR (Color){.r = 0xb4, .g = 0x65, .b = 0x4a, .a = 0xff}
+#define WANDERER_COUNT 50000
+#define ZONE_COUNT 5
+#define WANDERER_SLOWDOWN_FACTOR 0.5f
+#define WANDERER_SPEEDUP_FACTOR 2.0f
+#define MSG_BUF_LEN 4096
+#define abs(A) (A < 0 ? A * -1 : A)
+#define min(A, B) (A < B ? A : B)
+#define max(A, B) (A > B ? A : B)
+
+#define OBJECT_COMMON struct {Position position; Scale scale;}
+
+typedef struct Position Position;
+struct Position {
+  f32 x;
+  f32 y;
+};
+
+typedef struct Scale Scale;
+struct Scale {
+  f32 width;
+  f32 height;
+};
+
+typedef struct Velocity Velocity;
+struct Velocity {
+  f32 x;
+  f32 y;
+};
+
+typedef struct Wanderer Wanderer;
+struct Wanderer {
+  OBJECT_COMMON;
+  Velocity velocity;
+  bool slow;
+};
+
+typedef struct SlowZone SlowZone;
+struct SlowZone {
+  OBJECT_COMMON;
+};
+
+void init_wanderer(Wanderer *wanderer, XOR256State *state);
+void move_wanderer(Wanderer *wanderer, const SlowZone *zones);
+void render_wanderer(const Wanderer *wanderer);
+void init_slow_zone(SlowZone *zone,  XOR256State *state);
+
+#ifndef NDEBUG
+void render_slow_zone(const SlowZone *zone);
+#endif
+
+bool inside_zone(const Wanderer *wanderer, const SlowZone *zone);
+f32 get_random_float(XOR256State *state);
+
+int main(void) {
+  InitWindow(WIDTH, HEIGHT, "DOD test");
+  SetTargetFPS(120);
+
+  Allocator arena       = wapp_mem_arena_allocator_init(MB(10));
+  XOR256State state     = wapp_prng_xorshift_init_state();
+  Wanderer *wanderers   = wapp_mem_allocator_alloc(&arena, sizeof(Wanderer) * WANDERER_COUNT);
+  SlowZone *zones       = wapp_mem_allocator_alloc(&arena, sizeof(SlowZone) * ZONE_COUNT);
+  assert(wanderers != NULL && zones != NULL);
+
+  for (u64 i = 0; i < WANDERER_COUNT; ++i) {
+    init_wanderer(&(wanderers[i]), &state);
+  }
+  for (u64 i = 0; i < ZONE_COUNT; ++i) {
+    init_slow_zone(&(zones[i]),&state);
+  }
+
+  while (!WindowShouldClose()) {
+    for (u64 i = 0; i < WANDERER_COUNT; ++i) {
+      move_wanderer(&(wanderers[i]), zones);
+    }
+
+    BeginDrawing();
+
+    ClearBackground(BG_COLOR);
+
+#ifndef NDEBUG
+    for (u64 i = 0; i < ZONE_COUNT; ++i) {
+      render_slow_zone(&(zones[i]));
+    }
+#endif
+
+    for (u64 i = 0; i < WANDERER_COUNT; ++i) {
+      render_wanderer(&(wanderers[i]));
+    }
+
+    EndDrawing();
+  }
+
+  wapp_mem_arena_allocator_destroy(&arena);
+
+  CloseWindow();
+
+  return 0;
+}
+
+void init_wanderer(Wanderer *wanderer, XOR256State *state) {
+  wanderer->position = (Position){
+    .x = wapp_prng_xorshift_256(state) % WIDTH,
+    .y = wapp_prng_xorshift_256(state) % HEIGHT,
+  };
+
+  f32 scale = (f32)((wapp_prng_xorshift_256(state) % (MAX_WANDERER_DIM + 1 - MIN_WANDERER_DIM)) + MIN_WANDERER_DIM);
+  wanderer->scale = (Scale){
+    .width  = scale,
+    .height = scale,
+  };
+
+  wanderer->velocity = (Velocity){
+    .x = get_random_float(state),
+    .y = get_random_float(state),
+  };
+}
+
+void move_wanderer(Wanderer *wanderer, const SlowZone *zones) {
+  wanderer->position.x += wanderer->velocity.x;
+  wanderer->position.y += wanderer->velocity.y;
+
+  f32 max_x = WIDTH - wanderer->scale.width;
+  f32 max_y = HEIGHT - wanderer->scale.height;
+
+  if (wanderer->position.x < 0 || wanderer->position.x >= max_x) {
+    wanderer->position.x = min(max(wanderer->position.x, 0), max_x);
+    wanderer->velocity.x *= -1;
+  }
+
+  if (wanderer->position.y < 0 || wanderer->position.y >= max_y) {
+    wanderer->position.y = min(max(wanderer->position.y, 0), max_y);
+    wanderer->velocity.y *= -1;
+  }
+
+  bool was_slow  = wanderer->slow;
+  wanderer->slow = false;
+  for (u64 i = 0; i < ZONE_COUNT; ++i) {
+    if (inside_zone(wanderer, &(zones[i]))) {
+      wanderer->slow = true;
+      break;
+    }
+  }
+
+  if (!was_slow && wanderer->slow) {
+    wanderer->velocity.x *= WANDERER_SLOWDOWN_FACTOR;
+    wanderer->velocity.y *= WANDERER_SLOWDOWN_FACTOR;
+  } else if (was_slow && !(wanderer->slow)) {
+    wanderer->velocity.x *= WANDERER_SPEEDUP_FACTOR;
+    wanderer->velocity.y *= WANDERER_SPEEDUP_FACTOR;
+  }
+}
+
+void render_wanderer(const Wanderer *wanderer) {
+  Color color = wanderer->slow ? ZONE_COLOR : FG_COLOR;
+  DrawRectangle(
+    (i32)wanderer->position.x,
+    (i32)wanderer->position.y,
+    (i32)wanderer->scale.width,
+    (i32)wanderer->scale.height,
+    color
+  );
+}
+
+void init_slow_zone(SlowZone *zone,  XOR256State *state) {
+  zone->position = (Position){
+    .x = wapp_prng_xorshift_256(state) % WIDTH,
+    .y = wapp_prng_xorshift_256(state) % HEIGHT,
+  };
+
+  zone->scale = (Scale){
+    .width = wapp_prng_xorshift_256(state) % ((u64)HALF_WIDTH - MIN_ZONE_DIM) + MIN_ZONE_DIM,
+    .height = wapp_prng_xorshift_256(state) % ((u64)HALF_HEIGHT - MIN_ZONE_DIM) + MIN_ZONE_DIM,
+  };
+}
+
+#ifndef NDEBUG
+void render_slow_zone(const SlowZone *zone) {
+  DrawRectangleLines(
+    zone->position.x,
+    zone->position.y,
+    zone->scale.width,
+    zone->scale.height,
+    ZONE_COLOR
+  );
+}
+#endif
+
+bool inside_zone(const Wanderer *wanderer, const SlowZone *zone) {
+  f32 wanderer_min_x = wanderer->position.x + wanderer->scale.width;
+  f32 wanderer_min_y = wanderer->position.y + wanderer->scale.height;
+  f32 wanderer_max_x = wanderer->position.x;
+  f32 wanderer_max_y = wanderer->position.y;
+
+  f32 zone_x0 = zone->position.x;
+  f32 zone_y0 = zone->position.y;
+  f32 zone_x1 = zone->position.x + zone->scale.width;
+  f32 zone_y1 = zone->position.y + zone->scale.height;
+
+  return (wanderer_min_x > zone_x0 && wanderer_min_y > zone_y0 &&
+          wanderer_max_x < zone_x1 && wanderer_max_y < zone_y1);
+}
+
+f32 get_random_float(XOR256State *state) {
+  i64 random = (i64)wapp_prng_xorshift_256(state) - INT64_MAX;
+  return (f32)(random) / (f32)(INT64_MAX);
+}
diff --git a/test b/test
index b26d3fd..884d56d 100755
--- a/test
+++ b/test
@@ -1,4 +1,4 @@
 #!/bin/bash
 
 ./build $@
-./main
+./no_dod