diff --git a/.gitignore b/.gitignore
index 8fbd6e6..ebae9ef 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 main
 save.dat
+munit/
diff --git a/Makefile b/Makefile
index 8b68f6a..c437fc4 100644
--- a/Makefile
+++ b/Makefile
@@ -4,6 +4,8 @@ LIBS = -lraylib -lm -lpthread -ldl
 
 TARGET = main
 SRC = main.c game.c ui.c
+TEST_TARGET = munit_tests
+TEST_SRC = munit.c game.c munit/munit.c
 
 all: $(TARGET)
 
@@ -16,4 +18,10 @@ clean:
 run: $(TARGET)
 	./$(TARGET)
 
-.PHONY: all clean run
+test: $(TEST_TARGET)
+	./$(TEST_TARGET)
+
+$(TEST_TARGET): $(TEST_SRC)
+	$(CC) $(CFLAGS) $(TEST_SRC) -o $(TEST_TARGET) $(LIBS)
+
+.PHONY: all clean run test
diff --git a/main.c b/main.c
index 821807d..95b0bf8 100644
--- a/main.c
+++ b/main.c
@@ -25,12 +25,21 @@ int main() {
 
   SetConfigFlags(FLAG_WINDOW_HIGHDPI);
   InitWindow(WINDOW_WIDTH, WINDOW_HEIGHT, "2048");
-  SetTargetFPS(30); // So my laptop doesn't burn
+  SetTargetFPS(90); // We have event blocking so we can affort higher FPS
+  EnableEventWaiting();
 
   while (!WindowShouldClose()) {
-    ClearBackground(RAYWHITE);
     BeginDrawing();
-    render(&game_state);
+    ClearBackground(RAYWHITE);
+
+    // If we are not animating, we can wait for input events instead of continuously rendering
+    bool animating = render(&game_state);
+    if (animating) {
+      DisableEventWaiting();
+    } else {
+      EnableEventWaiting();
+    }
+
     EndDrawing();
     handle_mouse_input(&game_state);
     handle_keyboard_input(&game_state);
diff --git a/munit.c b/munit.c
new file mode 100644
index 0000000..7396aa3
--- /dev/null
+++ b/munit.c
@@ -0,0 +1,370 @@
+#include "munit/munit.h"
+#include "game.h"
+
+#include <stdlib.h>
+
+static void clear_tiles(GameState_t *state) {
+  for (int y = 0; y < BOARD_HEIGHT; y++) {
+    for (int x = 0; x < BOARD_WIDTH; x++) {
+      state->board[y][x] = 0;
+    }
+  }
+}
+
+static void *test_setup(const MunitParameter params[], void *user_data) {
+  (void)params;
+  (void)user_data;
+
+  GameState_t *state = (GameState_t *)malloc(sizeof(GameState_t));
+  munit_assert_not_null(state);
+
+  reset_board(state);
+  clear_tiles(state);
+  return state;
+}
+
+static void test_tear_down(void *fixture) {
+  free(fixture);
+}
+
+static MunitResult test_merge_left_simple(const MunitParameter params[], void *fixture) {
+  (void)params;
+  GameState_t *state = (GameState_t *)fixture;
+
+  state->board[0][0] = 2;
+  state->board[0][1] = 2;
+
+  munit_assert_true(move(state, LEFT));
+  munit_assert_int(state->board[0][0], ==, 4);
+  munit_assert_int(state->board[0][1], ==, 0);
+  munit_assert_uint(state->score, ==, 4);
+  munit_assert_uint(state->moves_made, ==, 1);
+
+  return MUNIT_OK;
+}
+
+static MunitResult test_merge_left_through_gap(const MunitParameter params[], void *fixture) {
+  (void)params;
+  GameState_t *state = (GameState_t *)fixture;
+
+  state->board[0][0] = 2;
+  state->board[0][2] = 2;
+
+  munit_assert_true(move(state, LEFT));
+  munit_assert_int(state->board[0][0], ==, 4);
+  munit_assert_int(state->board[0][1], ==, 0);
+  munit_assert_int(state->board[0][2], ==, 0);
+  munit_assert_int(state->board[0][3], ==, 0);
+
+  return MUNIT_OK;
+}
+
+static MunitResult test_merge_left_double_pair(const MunitParameter params[], void *fixture) {
+  (void)params;
+  GameState_t *state = (GameState_t *)fixture;
+
+  state->board[0][0] = 2;
+  state->board[0][1] = 2;
+  state->board[0][2] = 4;
+  state->board[0][3] = 4;
+
+  munit_assert_true(move(state, LEFT));
+  munit_assert_int(state->board[0][0], ==, 4);
+  munit_assert_int(state->board[0][1], ==, 8);
+  munit_assert_int(state->board[0][2], ==, 0);
+  munit_assert_int(state->board[0][3], ==, 0);
+  munit_assert_uint(state->score, ==, 12);
+
+  return MUNIT_OK;
+}
+
+static MunitResult test_merge_left_no_double_merge_single_move(const MunitParameter params[], void *fixture) {
+  (void)params;
+  GameState_t *state = (GameState_t *)fixture;
+
+  state->board[0][0] = 2;
+  state->board[0][1] = 2;
+  state->board[0][2] = 2;
+
+  munit_assert_true(move(state, LEFT));
+  munit_assert_int(state->board[0][0], ==, 4);
+  munit_assert_int(state->board[0][1], ==, 2);
+  munit_assert_int(state->board[0][2], ==, 0);
+  munit_assert_int(state->board[0][3], ==, 0);
+  munit_assert_uint(state->score, ==, 4);
+
+  return MUNIT_OK;
+}
+
+static MunitResult test_move_left_no_merge_when_different_values(const MunitParameter params[], void *fixture) {
+  (void)params;
+  GameState_t *state = (GameState_t *)fixture;
+
+  state->board[0][1] = 2;
+  state->board[0][2] = 4;
+
+  munit_assert_true(move(state, LEFT));
+  munit_assert_int(state->board[0][0], ==, 2);
+  munit_assert_int(state->board[0][1], ==, 4);
+  munit_assert_int(state->board[0][2], ==, 0);
+  munit_assert_int(state->board[0][3], ==, 0);
+  munit_assert_uint(state->score, ==, 0);
+
+  return MUNIT_OK;
+}
+
+static MunitResult test_move_returns_false_when_nothing_changes(const MunitParameter params[], void *fixture) {
+  (void)params;
+  GameState_t *state = (GameState_t *)fixture;
+
+  state->board[0][0] = 2;
+  state->board[0][1] = 4;
+  state->board[0][2] = 8;
+  state->board[0][3] = 16;
+
+  munit_assert_false(move(state, LEFT));
+  munit_assert_uint(state->moves_made, ==, 0);
+  munit_assert_uint(state->score, ==, 0);
+
+  return MUNIT_OK;
+}
+
+static MunitResult test_merge_right_simple(const MunitParameter params[], void *fixture) {
+  (void)params;
+  GameState_t *state = (GameState_t *)fixture;
+
+  state->board[1][2] = 2;
+  state->board[1][3] = 2;
+
+  munit_assert_true(move(state, RIGHT));
+  munit_assert_int(state->board[1][0], ==, 0);
+  munit_assert_int(state->board[1][1], ==, 0);
+  munit_assert_int(state->board[1][2], ==, 0);
+  munit_assert_int(state->board[1][3], ==, 4);
+
+  return MUNIT_OK;
+}
+
+static MunitResult test_merge_right_through_gap(const MunitParameter params[], void *fixture) {
+  (void)params;
+  GameState_t *state = (GameState_t *)fixture;
+
+  state->board[1][1] = 2;
+  state->board[1][3] = 2;
+
+  munit_assert_true(move(state, RIGHT));
+  munit_assert_int(state->board[1][0], ==, 0);
+  munit_assert_int(state->board[1][1], ==, 0);
+  munit_assert_int(state->board[1][2], ==, 0);
+  munit_assert_int(state->board[1][3], ==, 4);
+
+  return MUNIT_OK;
+}
+
+static MunitResult test_merge_right_double_pair(const MunitParameter params[], void *fixture) {
+  (void)params;
+  GameState_t *state = (GameState_t *)fixture;
+
+  state->board[1][0] = 2;
+  state->board[1][1] = 2;
+  state->board[1][2] = 4;
+  state->board[1][3] = 4;
+
+  munit_assert_true(move(state, RIGHT));
+  munit_assert_int(state->board[1][0], ==, 0);
+  munit_assert_int(state->board[1][1], ==, 0);
+  munit_assert_int(state->board[1][2], ==, 4);
+  munit_assert_int(state->board[1][3], ==, 8);
+  munit_assert_uint(state->score, ==, 12);
+
+  return MUNIT_OK;
+}
+
+static MunitResult test_merge_right_no_double_merge_single_move(const MunitParameter params[], void *fixture) {
+  (void)params;
+  GameState_t *state = (GameState_t *)fixture;
+
+  state->board[1][1] = 2;
+  state->board[1][2] = 2;
+  state->board[1][3] = 2;
+
+  munit_assert_true(move(state, RIGHT));
+  munit_assert_int(state->board[1][0], ==, 0);
+  munit_assert_int(state->board[1][1], ==, 0);
+  munit_assert_int(state->board[1][2], ==, 2);
+  munit_assert_int(state->board[1][3], ==, 4);
+  munit_assert_uint(state->score, ==, 4);
+
+  return MUNIT_OK;
+}
+
+static MunitResult test_merge_up_simple(const MunitParameter params[], void *fixture) {
+  (void)params;
+  GameState_t *state = (GameState_t *)fixture;
+
+  state->board[0][0] = 2;
+  state->board[1][0] = 2;
+
+  munit_assert_true(move(state, UP));
+  munit_assert_int(state->board[0][0], ==, 4);
+  munit_assert_int(state->board[1][0], ==, 0);
+  munit_assert_int(state->board[2][0], ==, 0);
+  munit_assert_int(state->board[3][0], ==, 0);
+
+  return MUNIT_OK;
+}
+
+static MunitResult test_merge_up_through_gap(const MunitParameter params[], void *fixture) {
+  (void)params;
+  GameState_t *state = (GameState_t *)fixture;
+
+  state->board[0][1] = 2;
+  state->board[2][1] = 2;
+
+  munit_assert_true(move(state, UP));
+  munit_assert_int(state->board[0][1], ==, 4);
+  munit_assert_int(state->board[1][1], ==, 0);
+  munit_assert_int(state->board[2][1], ==, 0);
+  munit_assert_int(state->board[3][1], ==, 0);
+
+  return MUNIT_OK;
+}
+
+static MunitResult test_merge_up_double_pair(const MunitParameter params[], void *fixture) {
+  (void)params;
+  GameState_t *state = (GameState_t *)fixture;
+
+  state->board[0][1] = 2;
+  state->board[1][1] = 2;
+  state->board[2][1] = 4;
+  state->board[3][1] = 4;
+
+  munit_assert_true(move(state, UP));
+  munit_assert_int(state->board[0][1], ==, 4);
+  munit_assert_int(state->board[1][1], ==, 8);
+  munit_assert_int(state->board[2][1], ==, 0);
+  munit_assert_int(state->board[3][1], ==, 0);
+  munit_assert_uint(state->score, ==, 12);
+
+  return MUNIT_OK;
+}
+
+static MunitResult test_merge_up_no_double_merge_single_move(const MunitParameter params[], void *fixture) {
+  (void)params;
+  GameState_t *state = (GameState_t *)fixture;
+
+  state->board[0][1] = 2;
+  state->board[1][1] = 2;
+  state->board[2][1] = 2;
+
+  munit_assert_true(move(state, UP));
+  munit_assert_int(state->board[0][1], ==, 4);
+  munit_assert_int(state->board[1][1], ==, 2);
+  munit_assert_int(state->board[2][1], ==, 0);
+  munit_assert_int(state->board[3][1], ==, 0);
+  munit_assert_uint(state->score, ==, 4);
+
+  return MUNIT_OK;
+}
+
+static MunitResult test_merge_down_simple(const MunitParameter params[], void *fixture) {
+  (void)params;
+  GameState_t *state = (GameState_t *)fixture;
+
+  state->board[1][2] = 2;
+  state->board[2][2] = 2;
+
+  munit_assert_true(move(state, DOWN));
+  munit_assert_int(state->board[0][2], ==, 0);
+  munit_assert_int(state->board[1][2], ==, 0);
+  munit_assert_int(state->board[2][2], ==, 0);
+  munit_assert_int(state->board[3][2], ==, 4);
+
+  return MUNIT_OK;
+}
+
+static MunitResult test_merge_down_through_gap(const MunitParameter params[], void *fixture) {
+  (void)params;
+  GameState_t *state = (GameState_t *)fixture;
+
+  state->board[0][2] = 2;
+  state->board[2][2] = 2;
+
+  munit_assert_true(move(state, DOWN));
+  munit_assert_int(state->board[0][2], ==, 0);
+  munit_assert_int(state->board[1][2], ==, 0);
+  munit_assert_int(state->board[2][2], ==, 0);
+  munit_assert_int(state->board[3][2], ==, 4);
+
+  return MUNIT_OK;
+}
+
+static MunitResult test_merge_down_double_pair(const MunitParameter params[], void *fixture) {
+  (void)params;
+  GameState_t *state = (GameState_t *)fixture;
+
+  state->board[0][2] = 2;
+  state->board[1][2] = 2;
+  state->board[2][2] = 4;
+  state->board[3][2] = 4;
+
+  munit_assert_true(move(state, DOWN));
+  munit_assert_int(state->board[0][2], ==, 0);
+  munit_assert_int(state->board[1][2], ==, 0);
+  munit_assert_int(state->board[2][2], ==, 4);
+  munit_assert_int(state->board[3][2], ==, 8);
+  munit_assert_uint(state->score, ==, 12);
+
+  return MUNIT_OK;
+}
+
+static MunitResult test_merge_down_no_double_merge_single_move(const MunitParameter params[], void *fixture) {
+  (void)params;
+  GameState_t *state = (GameState_t *)fixture;
+
+  state->board[1][2] = 2;
+  state->board[2][2] = 2;
+  state->board[3][2] = 2;
+
+  munit_assert_true(move(state, DOWN));
+  munit_assert_int(state->board[0][2], ==, 0);
+  munit_assert_int(state->board[1][2], ==, 0);
+  munit_assert_int(state->board[2][2], ==, 2);
+  munit_assert_int(state->board[3][2], ==, 4);
+  munit_assert_uint(state->score, ==, 4);
+
+  return MUNIT_OK;
+}
+
+static MunitTest tests[] = {
+    {(char *)"/merge/left/simple", test_merge_left_simple, test_setup, test_tear_down, MUNIT_TEST_OPTION_NONE, NULL},
+    {(char *)"/merge/left/through-gap", test_merge_left_through_gap, test_setup, test_tear_down, MUNIT_TEST_OPTION_NONE, NULL},
+    {(char *)"/merge/left/double-pair", test_merge_left_double_pair, test_setup, test_tear_down, MUNIT_TEST_OPTION_NONE, NULL},
+    {(char *)"/merge/left/no-double-merge", test_merge_left_no_double_merge_single_move, test_setup, test_tear_down, MUNIT_TEST_OPTION_NONE, NULL},
+    {(char *)"/merge/left/different-values-no-merge", test_move_left_no_merge_when_different_values, test_setup, test_tear_down, MUNIT_TEST_OPTION_NONE, NULL},
+    {(char *)"/move/no-change", test_move_returns_false_when_nothing_changes, test_setup, test_tear_down, MUNIT_TEST_OPTION_NONE, NULL},
+    {(char *)"/merge/right/simple", test_merge_right_simple, test_setup, test_tear_down, MUNIT_TEST_OPTION_NONE, NULL},
+    {(char *)"/merge/right/through-gap", test_merge_right_through_gap, test_setup, test_tear_down, MUNIT_TEST_OPTION_NONE, NULL},
+    {(char *)"/merge/right/double-pair", test_merge_right_double_pair, test_setup, test_tear_down, MUNIT_TEST_OPTION_NONE, NULL},
+    {(char *)"/merge/right/no-double-merge", test_merge_right_no_double_merge_single_move, test_setup, test_tear_down, MUNIT_TEST_OPTION_NONE, NULL},
+    {(char *)"/merge/up/simple", test_merge_up_simple, test_setup, test_tear_down, MUNIT_TEST_OPTION_NONE, NULL},
+    {(char *)"/merge/up/through-gap", test_merge_up_through_gap, test_setup, test_tear_down, MUNIT_TEST_OPTION_NONE, NULL},
+    {(char *)"/merge/up/double-pair", test_merge_up_double_pair, test_setup, test_tear_down, MUNIT_TEST_OPTION_NONE, NULL},
+    {(char *)"/merge/up/no-double-merge", test_merge_up_no_double_merge_single_move, test_setup, test_tear_down, MUNIT_TEST_OPTION_NONE, NULL},
+    {(char *)"/merge/down/simple", test_merge_down_simple, test_setup, test_tear_down, MUNIT_TEST_OPTION_NONE, NULL},
+    {(char *)"/merge/down/through-gap", test_merge_down_through_gap, test_setup, test_tear_down, MUNIT_TEST_OPTION_NONE, NULL},
+    {(char *)"/merge/down/double-pair", test_merge_down_double_pair, test_setup, test_tear_down, MUNIT_TEST_OPTION_NONE, NULL},
+    {(char *)"/merge/down/no-double-merge", test_merge_down_no_double_merge_single_move, test_setup, test_tear_down, MUNIT_TEST_OPTION_NONE, NULL},
+    {NULL, NULL, NULL, NULL, MUNIT_TEST_OPTION_NONE, NULL}};
+
+static const MunitSuite suite = {
+    (char *)"",
+    tests,
+    NULL,
+    1,
+    MUNIT_SUITE_OPTION_NONE,
+};
+
+int main(int argc, char *argv[MUNIT_ARRAY_PARAM(argc + 1)]) {
+  return munit_suite_main(&suite, NULL, argc, argv);
+}
diff --git a/munit_tests b/munit_tests
new file mode 100755
index 0000000..94b7b86
Binary files /dev/null and b/munit_tests differ
diff --git a/ui.c b/ui.c
index a36ef56..c65aa09 100644
--- a/ui.c
+++ b/ui.c
@@ -30,6 +30,16 @@ static bool is_animating;
 static Vector2 new_tile = {-1, 1};
 static float new_tile_animation_progress;
 
+typedef struct {
+  Vector2 from;
+  Vector2 to;
+  // We need to store this to know when to (show the) merge, if merging
+  Vector2 position;
+  int value;
+} animated_tile_t;
+
+static animated_tile_t animated_tiles[BOARD_WIDTH * BOARD_HEIGHT];
+
 // Common logic shared between both input handlers
 static void after_input(GameState_t *game_state) {
   spawn_tile(game_state, &new_tile);
@@ -132,21 +142,20 @@ void handle_keyboard_input(GameState_t *game_state) {
   }
 }
 
-void animate_new_tile() {
+static void animate_new_tile() {
   if (new_tile.x == -1 && new_tile.y == -1)
     return;
 
-  // Simple pop-in animation that scales the tile from 0 to full size
-  new_tile_animation_progress += GetFrameTime() * 5; // Adjust speed as needed
+  new_tile_animation_progress += GetFrameTime() * 5;
   if (new_tile_animation_progress >= 1.0f) {
-    new_tile_animation_progress = 0.3f;
+    new_tile_animation_progress = 0.0f;
     new_tile = (Vector2){-1, -1}; // Reset after animation completes
     is_animating = false;
   }
 }
 
 // Main render loop, responsible ONLY for redering
-void render(GameState_t *game_state) {
+bool render(GameState_t *game_state) {
   if (is_animating) {
     animate_new_tile();
   }
@@ -163,7 +172,7 @@ void render(GameState_t *game_state) {
       }
 
       if (is_animating && new_tile.x == x && new_tile.y == y) {
-        float scale = new_tile_animation_progress; // Scale from 0 to 1
+        float scale = 1.0 - 0.2 * sin(new_tile_animation_progress * PI);
         int scaled_size = (int)(TILE_SIZE * scale);
         int offset = (TILE_SIZE - scaled_size) / 2;
         DrawRectangle(pos_x + offset, pos_y + offset, scaled_size, scaled_size, tile_colors[color_index]);
@@ -207,4 +216,5 @@ void render(GameState_t *game_state) {
     DrawRectangle(400 - 100, 450, 200, 40, RED);
     DrawText("Try again", 400 - MeasureText("Try again", 20) / 2, 455 + 4, 20, WHITE);
   }
+  return is_animating;
 }
diff --git a/ui.h b/ui.h
index 4e38c5e..01a87e9 100644
--- a/ui.h
+++ b/ui.h
@@ -9,6 +9,6 @@
 #define WINDOW_WIDTH 800
 #define WINDOW_HEIGHT 600
 
-void render(GameState_t *game_state);
+bool render(GameState_t *game_state);
 void handle_mouse_input(GameState_t *game_state);
 void handle_keyboard_input(GameState_t *game_state);