diff --git a/nes/eznes.h b/nes/eznes.h
index eb2f9e5..42d32f9 100644
--- a/nes/eznes.h
+++ b/nes/eznes.h
@@ -52,7 +52,7 @@ void ppu_on() {
   PPU.mask |= 0x1A;
 }
 
-int joy_input_wait() {
+u8 joy_input_wait() {
   u8 last_joy = 0, joy, pressed;
   /* wait until the previous key is released */
   while(joy_read(JOY_1));
@@ -88,7 +88,7 @@ void init_palette(u8 bg, u8 c1, u8 c2, u8 c3, u8 c4) {
 
 /* 4x4 char block colorization method (palette is 0 to 3) */
 void colorxy(u8 x, u8 y, u8 palette) {
-  unsigned int addr;
+  u16 addr;
   u8 attr_byte;
   addr = 0x23C0 + ((y >> 2) << 3) + (x >> 2);
   attr_byte = palette | (palette << 2) | (palette << 4) | (palette << 6);
@@ -100,25 +100,25 @@ void colorxy(u8 x, u8 y, u8 palette) {
 
 /* Sound section */
 
-unsigned int get_timer_by_freq(int freq) {
-  return (unsigned int) ((CPU / 16 / freq) - 1);
+u16 get_timer_by_freq(u16 freq) {
+  return (u16) ((CPU / 16 / freq) - 1);
 }
 
-void play_pulse(u8 idx, unsigned int freq, u8 len) {
-  unsigned int tm = get_timer_by_freq(freq);
+void play_pulse(u8 idx, u16 freq, u8 len) {
+  u16 tm = get_timer_by_freq(freq);
   if(len > 31) len = 31;
   if(idx > 1) idx = 0;
   APU.pulse[idx].period_low = tm & 255;
   APU.pulse[idx].len_period_high = (tm >> 8) | (len << 3);
 }
 
-void play_jingle(unsigned int n1f1,
-  unsigned int n1f2,
-  unsigned int n2f1,
-  unsigned int n2f2,
-  unsigned int n3f1,
-  unsigned int n3f2) {
-  unsigned int i, dl = 2000;
+void play_jingle(u16 n1f1,
+  u16 n1f2,
+  u16 n2f1,
+  u16 n2f2,
+  u16 n3f1,
+  u16 n3f2) {
+  u16 i, dl = 2000;
   play_pulse(0, n1f1, 2);
   play_pulse(1, n1f2, 2);
   for(i=0;i<dl;++i);
@@ -165,7 +165,7 @@ void wait_for_start() {
 /* randomize until Start is pressed */
 void wait_for_start_rand() {
   u8 joy;
-  unsigned int entropy = rand();
+  u16 entropy = rand();
   while(1) {
     ++entropy;
     joy = joy_read(JOY_1);
diff --git a/nes/nescoundrel.c b/nes/nescoundrel.c
index 39ed712..2e2bccd 100644
--- a/nes/nescoundrel.c
+++ b/nes/nescoundrel.c
@@ -155,13 +155,14 @@ static char deck[44], room[] = {0, 0, 0, 0};
 static char status_msg[(SCREEN_WIDTH-1)];
 
 /* tracking variables */
-static s16 deck_idx = 0, hp = 20, rooms_cleared = 0,
+static s16 hp = 20;
+static u8 deck_idx = 0, rooms_cleared = 0,
   weapon = 0, durability = 0, can_run = 1,
   engaged = 0, potion_drank = 0, last_potion_val = 0;
 
 /* Input method */
 /* up 1, left 2, right 3, down 4, a run, start quit */
-char get_choice() {
+u8 get_choice() {
   switch(joy_input_wait()) {
     case EZJOY_UP: return CH1;
     case EZJOY_LT: return CH2;
@@ -173,11 +174,9 @@ char get_choice() {
 }
 
 /* Draw a room character according to the index and value */
-void render_room_item(s16 i, s16 v) {
-  u8 color,
-        topleft_x, topleft_y,
-        topright_x, bottomleft_y,
-        text_x, text_y, cheight=7, cwidth=8, left_offset = 9;
+void render_room_item(u8 i, u8 v) {
+  u8 color, topleft_x, topleft_y, topright_x, bottomleft_y,
+      text_x, text_y, cheight=7, cwidth=8, left_offset = 9;
   if(i == 0) {
     topleft_x = 8;
     topleft_y = 0;
@@ -300,7 +299,7 @@ void print_msg(char *s) {
 }
 
 /* Array shuffle method */
-void shuffle(char *array, u16 n) {
+void shuffle(s8 *array, u16 n) {
   u16 i, j, t;
   if(n > 1) {
     for(i=n-1;i>0;i--) {
@@ -338,7 +337,7 @@ s16 handle_monster(s16 val) {
   return val;
 }
 
-void handle_weapon(s16 val) {
+void handle_weapon(u8 val) {
   weapon = val;
   snprintf(status_msg, sizeof(status_msg), "You equip a %d-level weapon.", weapon);
   durability = 14; /* reset durability to max limit */
@@ -366,7 +365,7 @@ s16 game() {
   s16 score = -208; /* score storage */
   s16 item, room_sum; /* true item value */
   s16 last_room = 0, last_room_clr = 0; /* last room markers */
-  char ch;
+  u8 ch;
   deck_idx = 0; /* reset the deck index */
   /* Prefill the deck */
   for(i=0;i<13;i++) deck[i] = deck[i+13] = i+1;
@@ -457,8 +456,8 @@ s16 game() {
       engaged++; /* increase the amount of engaged cards */
       can_run = 0; /* Cannot run once engaged */
 
-      item = room[(int)ch]; /* get the item from the room */
-      room[(int)ch] = 0; /* mark the room slot as empty */
+      item = room[ch]; /* get the item from the room */
+      room[ch] = 0; /* mark the room slot as empty */
       /* Note: We do NOT put the item back in deck. It is consumed. */
 
       if(item < 14) { /* monster */