diff --git a/src/enemy/acroBandits.c b/src/enemy/acroBandits.c
index 463693f2..d240ecab 100644
--- a/src/enemy/acroBandits.c
+++ b/src/enemy/acroBandits.c
@@ -75,7 +75,7 @@ void AcroBandit_OnCollision(Entity* this) {
         if (this->type == 1) {
             if (this->action < 7 && this->knockbackDuration != 0) {
                 brother = this->child;
-                if (brother) {
+                if (brother != NULL) {
                     brother->parent = this->parent;
                     do {
                         brother->action = 5;
@@ -181,6 +181,7 @@ void AcroBandit_Type0Action1(Entity* this) {
 
 void AcroBandit_Type0Action2(Entity* this) {
     static const u8 actionDelays[] = { 2, 2, 2, 3, 3, 3, 3, 4 };
+
     GetNextFrame(this);
     if (this->frame & 1) {
         this->frame = 0;
@@ -318,14 +319,14 @@ void AcroBandit_Type0Action8(Entity* this) {
     }
 }
 
-u32 sub_08031E04(Entity* this) {
+bool32 sub_08031E04(Entity* this) {
     static const s8 gUnk_080CE5C0[] = { -32, 0, 0, 32, 32, 0, 0, 0 };
     Entity* ent;
     const s8* tmp;
 
     ent = sub_08049DF4(1);
     if (ent == NULL)
-        return 0;
+        return FALSE;
 
     tmp = &gUnk_080CE5C0[this->frame & 6];
     return EntityWithinDistance(this, ent->x.HALF.HI + tmp[0], ent->y.HALF.HI + tmp[1], 0x50);
@@ -386,6 +387,7 @@ void AcroBandit_Type1Action1(Entity* this) {
 
 void AcroBandit_Type1Action2(Entity* this) {
     static const u16 banditGravity[] = { 0x1600, 0x1300, 0x1000, 0xD00, 0xB00 };
+
     GravityUpdate(this, banditGravity[this->type2]);
     if (this->type2 * -0xe <= this->z.HALF.HI) {
         this->action = 3;
@@ -399,7 +401,7 @@ void AcroBandit_Type1Action2(Entity* this) {
 
 void AcroBandit_Type1Action3(Entity* this) {
     GetNextFrame(this);
-    if ((this->frame & ANIM_DONE) && (this->parent || --this->actionDelay == 0)) {
+    if ((this->frame & ANIM_DONE) && ((this->parent != NULL) || (--this->actionDelay == 0))) {
         this->action = 4;
         this->direction = sub_08049F84(this, 1);
         *(u8*)&this->field_0x76 = 0;
@@ -414,9 +416,9 @@ void AcroBandit_Type1Action3(Entity* this) {
 void AcroBandit_Type1Action4(Entity* this) {
     Entity* parent;
 
-    if (sub_080322A4(this) == 0) {
+    if (!sub_080322A4(this)) {
         parent = this->parent;
-        if (parent == 0) {
+        if (parent == NULL) {
             if (sub_08049FDC(this, 1)) {
                 if ((++this->field_0x78.HALF.HI & 7) == 0) {
                     sub_08004596(this, GetFacingDirection(this, gUnk_020000B0));
@@ -538,30 +540,29 @@ void sub_08032290(Entity* this) {
     InitializeAnimation(this, 11);
 }
 
-u32 sub_080322A4(Entity* this) {
+bool32 sub_080322A4(Entity* this) {
     if (this->child != NULL && (this->child->z.HALF.HI + 8) >= this->z.HALF.HI) {
         if (this->z.HALF.HI) {
             this->action = 5;
             this->z.HALF.HI = this->child->z.HALF.HI + 8;
             InitializeAnimation(this, 11);
-            return 1;
+            return TRUE;
         } else {
             sub_08032290(this);
-            return 1;
+            return TRUE;
         }
     }
-    return 0;
+    return FALSE;
 }
 
 void sub_080322E8(Entity* this) {
-    u8 tmp;
     if (this->field_0x78.HALF.LO) {
         if (--this->field_0x78.HALF.LO == 0) {
             u32 flipX = this->spriteSettings.flipX;
             this->spriteSettings.flipX = flipX ^ 1;
         }
     } else {
-        tmp = this->direction;
+        u8 tmp = this->direction;
         if (tmp & 0xF) {
             tmp >>= 4;
             tmp ^= 1;
diff --git a/src/enemy/miniSlime.c b/src/enemy/miniSlime.c
index 7c82d1d6..aba4510e 100644
--- a/src/enemy/miniSlime.c
+++ b/src/enemy/miniSlime.c
@@ -34,7 +34,7 @@ void MiniSlime_OnCollision(Entity* this) {
 
 void MiniSlime_OnDeath(Entity* this) {
     Entity* parent = this->parent;
-    if (this != parent && parent) {
+    if ((this != parent) && (parent != NULL)) {
         this->field_0x6c.HALF.LO &= 0x7f;
         this->parent->child = this->child;
         this->child->parent = this->parent;
diff --git a/src/enemy/spearMoblin.c b/src/enemy/spearMoblin.c
index 53412903..a824b803 100644
--- a/src/enemy/spearMoblin.c
+++ b/src/enemy/spearMoblin.c
@@ -380,7 +380,7 @@ bool32 sub_080288A4(Entity* this) {
 
 void sub_080288C0(Entity* this) {
     Entity* ent = this->child;
-    if (ent && (ent->bitfield & 0x80)) {
+    if ((ent != NULL) && (ent->bitfield & 0x80)) {
         this->knockbackDirection = ent->knockbackDirection;
         this->iframes = -ent->iframes;
         this->knockbackSpeed = ent->knockbackSpeed;
diff --git a/src/npc/tingleSiblings.c b/src/npc/tingleSiblings.c
index d7628afe..32d6ab05 100644
--- a/src/npc/tingleSiblings.c
+++ b/src/npc/tingleSiblings.c
@@ -117,7 +117,7 @@ void sub_08064EE8(Entity* this) {
         }
 
         fxEnt = CreateFx(this, confettiFx, 0);
-        if (fxEnt && bVar1 == 2) {
+        if ((fxEnt != NULL) && (bVar1 == 2)) {
             fxEnt->spriteSettings.flipX = 1;
         }
     }
diff --git a/src/object/book.c b/src/object/book.c
index f42b2f1d..89005c80 100644
--- a/src/object/book.c
+++ b/src/object/book.c
@@ -15,11 +15,9 @@ void Book(Entity* this) {
 }
 
 void sub_0809B3C4(Entity* this) {
-    u32 obtained;
-
-    obtained = GetInventoryValue(this->type + ITEM_QST_BOOK1);
+    u32 obtained = GetInventoryValue(this->type + ITEM_QST_BOOK1);
     if (this->type2 != 3) {
-        if (obtained) {
+        if (obtained != 0) {
             DeleteThisEntity();
         }
     } else {
@@ -55,22 +53,23 @@ void sub_0809B3C4(Entity* this) {
         case 1: {
             u32 scroll;
             u32 height;
+
             this->action = 3;
             scroll = (u16)gRoomControls.scroll_y - 0x10;
             height = (u16)this->y.HALF.HI - scroll;
             this->z.HALF.HI -= height;
-            return;
+            break;
         }
         case 2:
             this->action = 4;
-            return;
+            break;
         case 3:
             this->action = 5;
             this->subAction = 0;
             this->spritePriority.b0 = 3;
             break;
         default:
-            return;
+            break;
     }
 }
 
@@ -92,7 +91,7 @@ void sub_0809B4A8(Entity* this) {
         this->speed = 64;
         this->direction = 16;
 
-        gPlayerState.pushedObject = 0x9e;
+        gPlayerState.pushedObject = TREE_THORNS;
         gPlayerState.queued_action = PLAYER_PUSH;
         gPlayerState.flags |= PL_BUSY;
 
@@ -134,7 +133,7 @@ void sub_0809B56C(Entity* this) {
     SetFlag(this->field_0x86.HWORD);
 
     fx = CreateFx(this, FX_DEATH, 0);
-    if (fx) {
+    if (fx != NULL) {
         SortEntityAbove(this, fx);
     }
 }
@@ -152,9 +151,8 @@ void sub_0809B5EC(Entity* this) {
     if (this->spriteSettings.draw == 1) {
         switch (this->subAction) {
             case 0: {
-                Entity* parent;
-                parent = FindEntityByID(NPC, STURGEON, 7);
-                if (!parent) {
+                Entity* parent = FindEntityByID(NPC, STURGEON, 7);
+                if (parent == NULL) {
                     return;
                 }
                 if (parent->x.HALF.HI < this->x.HALF.HI) {
@@ -170,7 +168,7 @@ void sub_0809B5EC(Entity* this) {
                 break;
             }
             case 1: {
-                if (!this->parent || !this->parent->next) {
+                if ((this->parent == NULL) || (this->parent->next == NULL)) {
                     DeleteThisEntity();
                     return;
                 }
@@ -206,9 +204,8 @@ void sub_0809B5EC(Entity* this) {
 }
 
 u32 sub_0809B688(Entity* this) {
-    u32 ret;
+    u32 ret = EntityInRectRadius(this, &gPlayerEntity, 6, 12);
 
-    ret = EntityInRectRadius(this, &gPlayerEntity, 6, 12);
     if (ret == 1 && gPlayerState.field_0xd != 16) {
         ret = 0;
     }
@@ -217,8 +214,7 @@ u32 sub_0809B688(Entity* this) {
 }
 
 void sub_0809B6B0(Entity* parent, Entity* this) {
-    s32 offset;
-    offset = (s32)gUnk_08123D94[parent->animationState >> 1] << 16;
+    s32 offset = (s32)gUnk_08123D94[parent->animationState >> 1] << 16;
 
     PositionRelative(parent, this, 0, offset);
 
diff --git a/src/object/specialFx.c b/src/object/specialFx.c
index c5262d9c..dc51b4c4 100644
--- a/src/object/specialFx.c
+++ b/src/object/specialFx.c
@@ -144,6 +144,7 @@ void sub_080844E0(SpecialFxObject* this) {
     static const u8 gUnk_0811FAC8[] = { 0x03, 0x37, 0x38, 0x39 };
     static const u8 gUnk_0811FACC[] = { 0x17, 0x3e, 0x3f, 0x40 };
     const struct_0811F960* ptr;
+
     super->action = 1;
     super->flags &= ~0x80;
     super->spriteSettings.draw = 1;
@@ -219,7 +220,7 @@ void sub_08084680(SpecialFxObject* this) {
 }
 
 void sub_08084694(SpecialFxObject* this) {
-    if (!super->parent || !super->parent->next) {
+    if ((super->parent == NULL) || (super->parent->next == NULL)) {
         DeleteThisEntity();
     }
     GetNextFrame(super);
@@ -253,12 +254,15 @@ void sub_080846B0(SpecialFxObject* this) {
 
 void sub_0808471C(SpecialFxObject* this) {
     static const s8 gUnk_0811FB08[] = { -8, -8, 8, -8, -8, 8, 8, 8 };
+
     GetNextFrame(super);
     if (super->frame & ANIM_DONE) {
         u32 i;
+
         for (i = 0; i < 4; i++) {
             Entity* fx = CreateFx(super, 0x24, 0);
-            if (fx) {
+
+            if (fx != NULL) {
                 const s8* ptr = &gUnk_0811FB08[2 * i];
                 fx->x.HALF.HI += ptr[0];
                 fx->y.HALF.HI += ptr[1];
@@ -280,7 +284,7 @@ void sub_08084784(SpecialFxObject* this) {
 
 void sub_08084798(SpecialFxObject* this) {
     GetNextFrame(super);
-    if ((super->frame & ANIM_DONE) || !super->child->next) {
+    if ((super->frame & ANIM_DONE) || (super->child->next == NULL)) {
         DeleteThisEntity();
     }
 }