Add cursed apple: a status-effect apple that inverts controls

Eating a cursed apple inverts the snake's steering for
CURSE_DURATION_TICKS ticks, shown on the top screen while active. The
sprite is a recolored copy of the rotten-apple tile since all existing
sprite tiles are already in use.

source/game_render.cpp

@@ -100,6 +100,15 @@ void draw_apples_rotten(const GameState &state, const RenderAssets &assets, uint
     }
 }
 
+void draw_apples_cursed(const GameState &state, const RenderAssets &assets, uint16_t &oamId) {
+    for (const std::array<int, 2> &apple : state.cursed_apples) {
+        oamSet(&oamSub, oamId, apple[0] * 8, apple[1] * 8, 0, 0, SpriteSize_8x8,
+               SpriteColorFormat_256Color, assets.gfx_apple_cursed, -1, false, false, false, false,
+               false);
+        oamId++;
+    }
+}
+
 } // namespace
 
 void draw_game(const GameState &state, const RenderAssets &assets) {
@@ -108,6 +117,7 @@ void draw_game(const GameState &state, const RenderAssets &assets) {
     if (!state.gameOver) {
         draw_apples(state, assets, oamId);
         draw_apples_rotten(state, assets, oamId);
+        draw_apples_cursed(state, assets, oamId);
         draw_snake(state, assets, oamId);
         return;
     }
@@ -126,6 +136,12 @@ void draw_stats(const GameState &state, bool internals, bool musicEnabled, uint8
 
     iprintf("\x1b[10;12HScore: %i", state.score);
 
+    if (state.curseTicksRemaining > 0) {
+        iprintf("\x1b[1;7HCONTROLS INVERTED!");
+    } else {
+        iprintf("\x1b[1;7H                  ");
+    }
+
     if (!state.paused) {
         return;
     }