diff --git a/include/types.h b/include/types.h
index ca0094e9..7e65a583 100644
--- a/include/types.h
+++ b/include/types.h
@@ -174,7 +174,7 @@ struct GraphNodeObject
     /*0x20*/ Vec3f pos;
     /*0x2C*/ Vec3f scale;
     /*0x38*/ struct AnimInfo animInfo;
-    /*0x4C*/ struct SpawnInfo *unk4C;
+    /*0x4C*/ struct SpawnInfo *spawnInfo;
     /*0x50*/ Mat4 *throwMatrix; // matrix ptr
     /*0x54*/ Vec3f cameraToObject;
     u8 uCode;
diff --git a/src/audio/external.c b/src/audio/external.c
index a228607c..29b134b0 100644
--- a/src/audio/external.c
+++ b/src/audio/external.c
@@ -331,8 +331,6 @@ u8 sSoundBankDisabled[16] = { 0 };
 u8 D_80332108 = 0;
 u8 sHasStartedFadeOut = FALSE;
 u16 sSoundBanksThatLowerBackgroundMusic = 0;
-u8 sUnused80332114 = 0;  // never read, set to 0
-u16 sUnused80332118 = 0; // never read, set to 0
 u8 sBackgroundMusicMaxTargetVolume = TARGET_VOLUME_UNSET;
 u8 D_80332120 = 0;
 u8 D_80332124 = 0;
@@ -2142,11 +2140,9 @@ void sound_init(void) {
 
     sound_banks_enable(SEQ_PLAYER_SFX, SOUND_BANKS_ALL_BITS);
 
-    sUnused80332118 = 0;
     sBackgroundMusicTargetVolume = TARGET_VOLUME_UNSET;
     sLowerBackgroundMusicVolume = FALSE;
     sSoundBanksThatLowerBackgroundMusic = 0;
-    sUnused80332114 = 0;
     sCurrentBackgroundMusicSeqId = 0xff;
     gSoundMode = SOUND_MODE_STEREO;
     sBackgroundMusicQueueSize = 0;
@@ -2504,9 +2500,6 @@ void func_80320ED8(void) {
  * Called from threads: thread5_game_loop
  */
 void play_secondary_music(u8 seqId, u8 bgMusicVolume, u8 volume, u16 fadeTimer) {
-    UNUSED u32 dummy;
-
-    sUnused80332118 = 0;
     if (sCurrentBackgroundMusicSeqId == 0xff || sCurrentBackgroundMusicSeqId == SEQ_MENU_TITLE_SCREEN) {
         return;
     }
@@ -2530,6 +2523,7 @@ void play_secondary_music(u8 seqId, u8 bgMusicVolume, u8 volume, u16 fadeTimer)
 
 /**
  * Called from threads: thread5_game_loop
+ * Seems to be related to music fading based on position, such as sleeping Piranha Plants, BBH Merry-Go-Round, and Endless Stairs
  */
 void func_80321080(u16 fadeTimer) {
     if (sBackgroundMusicTargetVolume != TARGET_VOLUME_UNSET) {
diff --git a/src/engine/graph_node.c b/src/engine/graph_node.c
index 2f360ab5..aa0a9616 100644
--- a/src/engine/graph_node.c
+++ b/src/engine/graph_node.c
@@ -718,7 +718,7 @@ void geo_obj_init(struct GraphNodeObject *graphNode, void *sharedChild, Vec3f po
     vec3s_copy(graphNode->angle, angle);
 
     graphNode->sharedChild = sharedChild;
-    graphNode->unk4C = 0;
+    graphNode->spawnInfo = 0;
     graphNode->throwMatrix = NULL;
     graphNode->animInfo.curAnim = NULL;
 
@@ -742,7 +742,7 @@ void geo_obj_init_spawninfo(struct GraphNodeObject *graphNode, struct SpawnInfo
     graphNode->areaIndex = spawn->areaIndex;
     graphNode->activeAreaIndex = spawn->activeAreaIndex;
     graphNode->sharedChild = spawn->modelNode;
-    graphNode->unk4C = spawn;
+    graphNode->spawnInfo = spawn;
     graphNode->throwMatrix = NULL;
     graphNode->animInfo.curAnim = 0;
 
diff --git a/src/engine/surface_collision.c b/src/engine/surface_collision.c
index b5cc1f3a..749b99bc 100644
--- a/src/engine/surface_collision.c
+++ b/src/engine/surface_collision.c
@@ -15,6 +15,20 @@
  *                      WALLS                     *
  **************************************************/
 
+#define CALC_OFFSET(vert, next_step) {          \
+    if ((vert)[1] != 0.0f) {                    \
+        v = (v2[1] / (vert)[1]);                \
+        if ((v < 0.0f) || (v > 1.0f)) next_step;\
+        d00 = (((vert)[0] * v) - v2[0]);        \
+        d01 = (((vert)[2] * v) - v2[2]);        \
+        invDenom = sqrtf(sqr(d00) + sqr(d01));  \
+        offset   = (invDenom - margin_radius);  \
+        if (offset > 0.0f) next_step;           \
+        goto check_collision;                   \
+    }                                           \
+    next_step;                                  \
+}
+
 /**
  * Iterate through the list of walls until all walls are checked and
  * have given their wall push.
@@ -24,12 +38,8 @@ static s32 find_wall_collisions_from_list(struct SurfaceNode *surfaceNode, struc
     register struct Surface *surf;
     register f32 offset;
     register f32 radius = data->radius;
-    register f32 x = data->x;
-    register f32 y = data->y + data->offsetY;
-    register f32 z = data->z;
-    register f32 v0x, v0y, v0z;
-    register f32 v1x, v1y, v1z;
-    register f32 v2x, v2y, v2z;
+    register Vec3f pos = { data->x, data->y + data->offsetY, data->z };
+    register Vec3f v0, v1, v2;
     register f32 d00, d01, d11, d20, d21;
     register f32 invDenom;
     register f32 v, w;
@@ -57,11 +67,11 @@ static s32 find_wall_collisions_from_list(struct SurfaceNode *surfaceNode, struc
         surfaceNode = surfaceNode->next;
 
         // Exclude a large number of walls immediately to optimize.
-        if (y < surf->lowerY || y > surf->upperY) {
+        if (pos[1] < surf->lowerY || pos[1] > surf->upperY) {
             continue;
         }
 
-        offset = (surf->normal.x * x) + (surf->normal.y * y) + (surf->normal.z * z) + surf->originOffset;
+        offset = (surf->normal.x * pos[0]) + (surf->normal.y * pos[1]) + (surf->normal.z * pos[2]) + surf->originOffset;
 
         if (offset < -radius || offset > radius) {
             continue;
@@ -94,24 +104,24 @@ static s32 find_wall_collisions_from_list(struct SurfaceNode *surfaceNode, struc
             }
         }
 
-        v0x = (f32)(surf->vertex2[0] - surf->vertex1[0]);
-        v0y = (f32)(surf->vertex2[1] - surf->vertex1[1]);
-        v0z = (f32)(surf->vertex2[2] - surf->vertex1[2]);
+        v0[0] = (f32)(surf->vertex2[0] - surf->vertex1[0]);
+        v0[1] = (f32)(surf->vertex2[1] - surf->vertex1[1]);
+        v0[2] = (f32)(surf->vertex2[2] - surf->vertex1[2]);
 
-        v1x = (f32)(surf->vertex3[0] - surf->vertex1[0]);
-        v1y = (f32)(surf->vertex3[1] - surf->vertex1[1]);
-        v1z = (f32)(surf->vertex3[2] - surf->vertex1[2]);
+        v1[0] = (f32)(surf->vertex3[0] - surf->vertex1[0]);
+        v1[1] = (f32)(surf->vertex3[1] - surf->vertex1[1]);
+        v1[2] = (f32)(surf->vertex3[2] - surf->vertex1[2]);
 
-        v2x = x - (f32)surf->vertex1[0];
-        v2y = y - (f32)surf->vertex1[1];
-        v2z = z - (f32)surf->vertex1[2];
+        v2[0] = pos[0] - (f32)surf->vertex1[0];
+        v2[1] = pos[1] - (f32)surf->vertex1[1];
+        v2[2] = pos[2] - (f32)surf->vertex1[2];
 
         // Face
-        d00 = (v0x * v0x) + (v0y * v0y) + (v0z * v0z);
-        d01 = (v0x * v1x) + (v0y * v1y) + (v0z * v1z);
-        d11 = (v1x * v1x) + (v1y * v1y) + (v1z * v1z);
-        d20 = (v2x * v0x) + (v2y * v0y) + (v2z * v0z);
-        d21 = (v2x * v1x) + (v2y * v1y) + (v2z * v1z);
+        d00 = (v0[0] * v0[0]) + (v0[1] * v0[1]) + (v0[2] * v0[2]);
+        d01 = (v0[0] * v1[0]) + (v0[1] * v1[1]) + (v0[2] * v1[2]);
+        d11 = (v1[0] * v1[0]) + (v1[1] * v1[1]) + (v1[2] * v1[2]);
+        d20 = (v2[0] * v0[0]) + (v2[1] * v0[1]) + (v2[2] * v0[2]);
+        d21 = (v2[0] * v1[0]) + (v2[1] * v1[1]) + (v2[2] * v1[2]);
         invDenom = 1.0f / ((d00 * d11) - (d01 * d01));
         v = ((d11 * d20) - (d01 * d21)) * invDenom;
         if (v < 0.0f || v > 1.0f) {
@@ -121,97 +131,38 @@ static s32 find_wall_collisions_from_list(struct SurfaceNode *surfaceNode, struc
         if (w < 0.0f || w > 1.0f || v + w > 1.0f) {
             goto edge_1_2;
         }
-        x += surf->normal.x * (radius - offset);
-        z += surf->normal.z * (radius - offset);
+        pos[0] += surf->normal.x * (radius - offset);
+        pos[2] += surf->normal.z * (radius - offset);
         goto hasCollision;
 
     edge_1_2:
         if (offset < 0) continue;
-        // Edge 1-2
-        if (v0y != 0.0f) {
-            v = (v2y / v0y);
-            if (v < 0.0f || v > 1.0f) {
-                goto edge_1_3;
-            }
-            d00 = v0x * v - v2x;
-            d01 = v0z * v - v2z;
-            invDenom = sqrtf(sqr(d00) + sqr(d01));
-            offset = invDenom - margin_radius;
-            if (offset > 0.0f) {
-                goto edge_1_3;
-            }
-            invDenom = offset / invDenom;
-            x += (d00 *= invDenom);
-            z += (d01 *= invDenom);
-            margin_radius += 0.01f;
-
-            if ((d00 * surf->normal.x) + (d01 * surf->normal.z) < (corner_threshold * offset)) {
-                continue;
-            } else {
-                goto hasCollision;
-            }
-        }
-
+        CALC_OFFSET(v0, goto edge_1_3);
     edge_1_3:
-        // Edge 1-3
-        if (v1y != 0.0f) {
-            v = (v2y / v1y);
-            if (v < 0.0f || v > 1.0f) {
-                goto edge_2_3;
-            }
-            d00 = v1x * v - v2x;
-            d01 = v1z * v - v2z;
-            invDenom = sqrtf(sqr(d00) + sqr(d01));
-            offset = invDenom - margin_radius;
-            if (offset > 0.0f) {
-                goto edge_2_3;
-            }
-            invDenom = offset / invDenom;
-            x += (d00 *= invDenom);
-            z += (d01 *= invDenom);
-            margin_radius += 0.01f;
-
-            if ((d00 * surf->normal.x) + (d01 * surf->normal.z) < (corner_threshold * offset)) {
-                continue;
-            } else {
-                goto hasCollision;
-            }
-        }
-
+        CALC_OFFSET(v1, goto edge_2_3);
     edge_2_3:
         // Edge 2-3
-        v1x = (f32)(surf->vertex3[0] - surf->vertex2[0]);
-        v1y = (f32)(surf->vertex3[1] - surf->vertex2[1]);
-        v1z = (f32)(surf->vertex3[2] - surf->vertex2[2]);
+        v1[0] = (f32)(surf->vertex3[0] - surf->vertex2[0]);
+        v1[1] = (f32)(surf->vertex3[1] - surf->vertex2[1]);
+        v1[2] = (f32)(surf->vertex3[2] - surf->vertex2[2]);
 
-        v2x = x - (f32)surf->vertex2[0];
-        v2y = y - (f32)surf->vertex2[1];
-        v2z = z - (f32)surf->vertex2[2];
+        v2[0] = pos[0] - (f32)surf->vertex2[0];
+        v2[1] = pos[1] - (f32)surf->vertex2[1];
+        v2[2] = pos[2] - (f32)surf->vertex2[2];
 
-        if (v1y != 0.0f) {
-            v = (v2y / v1y);
-            if (v < 0.0f || v > 1.0f) continue;
-            d00 = v1x * v - v2x;
-            d01 = v1z * v - v2z;
-            invDenom = sqrtf(sqr(d00) + sqr(d01));
-            offset = invDenom - margin_radius;
-            if (offset > 0.0f) continue;
-            invDenom = offset / invDenom;
-            x += (d00 *= invDenom);
-            z += (d01 *= invDenom);
-            margin_radius += 0.01f;
-            if ((d00 * surf->normal.x) + (d01 * surf->normal.z) < (corner_threshold * offset)) {
-                continue;
-            } else {
-                goto hasCollision;
-            }
-        } else {
+        CALC_OFFSET(v1, continue);
+    check_collision:
+        invDenom = offset / invDenom;
+        pos[0] += (d00 *= invDenom);
+        pos[2] += (d01 *= invDenom);
+        margin_radius += 0.01f;
+        if ((d00 * surf->normal.x) + (d01 * surf->normal.z) < (corner_threshold * offset)) {
             continue;
         }
     hasCollision:
-        //! (Unreferenced Walls) Since this only returns the first four walls,
-        //  this can lead to wall interaction being missed. Typically unreferenced walls
-        //  come from only using one wall, however.
+        // (Unreferenced Walls) Since this only returns the first MAX_REFEREMCED_WALLS walls,
+        // this can lead to wall interaction being missed. Typically unreferenced walls
+        // come from only using one wall, however.
         if (data->numWalls < MAX_REFEREMCED_WALLS) {
             data->walls[data->numWalls++] = surf;
         }
@@ -225,8 +176,8 @@ static s32 find_wall_collisions_from_list(struct SurfaceNode *surfaceNode, struc
 //     z *= gWorldScale;
 // #endif
 
-    data->x = x;
-    data->z = z;
+    data->x = pos[0];
+    data->z = pos[2];
 
     return numCols;
 }
diff --git a/src/game/behaviors/bbh_merry_go_round.inc.c b/src/game/behaviors/bbh_merry_go_round.inc.c
index 91640fde..d1d047da 100644
--- a/src/game/behaviors/bbh_merry_go_round.inc.c
+++ b/src/game/behaviors/bbh_merry_go_round.inc.c
@@ -54,7 +54,7 @@ static void handle_merry_go_round_music(void) {
             // The merry-go-round is a dynamic surface.
             gMarioCurrentRoom != BBH_DYNAMIC_SURFACE_ROOM
             && gMarioCurrentRoom != BBH_NEAR_MERRY_GO_ROUND_ROOM) {
-            func_80321080(300); // Switch to BBH music? FIXME: Audio needs labelling
+            func_80321080(300); //! Switch to BBH music? FIXME: Audio needs labelling
             o->oMerryGoRoundMusicShouldPlay = FALSE;
         } else {
             cur_obj_play_sound_1(SOUND_ENV_MERRY_GO_ROUND_CREAKING);
@@ -95,6 +95,6 @@ void bhv_merry_go_round_loop(void) {
         handle_merry_go_round_music();
     } else {
         o->oAngleVelYaw = 0;
-        func_80321080(300); // Switch to BBH music? FIXME: Audio needs labelling
+        func_80321080(300); //! Switch to BBH music? FIXME: Audio needs labelling
     }
 }
diff --git a/src/goddard/objects.c b/src/goddard/objects.c
index 5e89f03a..dcb5fd71 100644
--- a/src/goddard/objects.c
+++ b/src/goddard/objects.c
@@ -1472,17 +1472,12 @@ void move_animator(struct ObjAnimator *animObj) {
 
 /* @ 22EDF4 for 0x300; orig name: func_80180624 */
 void drag_picked_object(struct GdObj *inputObj) {
-    UNUSED u32 spE4;
-    UNUSED u32 spE0;
-    UNUSED u32 spDC;
     struct GdVec3f displacement;
     struct GdVec3f spC4;
     struct GdControl *ctrl;
     Mat4f sp80;
     Mat4f sp40;
-    UNUSED u32 pad34[3];
     struct GdObj *obj;
-    UNUSED u32 pad2C;
     f32 dispMag;
 
     ctrl = &gGdCtrl;
@@ -1549,15 +1544,13 @@ void find_and_drag_picked_object(struct ObjGroup *group) {
 
 /* @ 22F180 for 0x624; orig name: func_801809B0 */
 void move_camera(struct ObjCamera *cam) {
-    struct GdObj *spEC;
-    struct GdVec3f spE0;
+    struct GdObj *obj;
+    struct GdVec3f worldPos;
     struct GdVec3f spD4;
     struct GdVec3f spC8;
-    UNUSED u8 padBC[0xC8 - 0xBC];
     struct GdVec3f spB0;
-    Mat4f sp70;
-    UNUSED u8 pad30[0x70 - 0x30];
-    Mat4f *sp2C;
+    Mat4f mtx;
+    Mat4f *idMtx;
     struct GdControl *ctrl;
 
     ctrl = &gGdCtrl;
@@ -1565,16 +1558,16 @@ void move_camera(struct ObjCamera *cam) {
         return;
     }
 
-    spE0.x = spE0.y = spE0.z = 0.0f;
+    worldPos.x = worldPos.y = worldPos.z = 0.0f;
     spB0.x = spB0.y = spB0.z = 0.0f;
 
-    if ((spEC = cam->unk30) != NULL) {
-        set_cur_dynobj(spEC);
-        d_get_world_pos(&spE0);
-        d_get_matrix(&sp70);
+    if ((obj = cam->unk30) != NULL) {
+        set_cur_dynobj(obj);
+        d_get_world_pos(&worldPos);
+        d_get_matrix(&mtx);
 
-        spC8.x = sp70[2][0] - cam->unk58;
-        spC8.z = sp70[2][2] - cam->unk60;
+        spC8.x = mtx[2][0] - cam->unk58;
+        spC8.z = mtx[2][2] - cam->unk60;
 
         cam->unk58 += spC8.x * cam->unk180.y;
         cam->unk60 += spC8.z * cam->unk180.y;
@@ -1597,7 +1590,7 @@ void move_camera(struct ObjCamera *cam) {
         gd_set_identity_mat4(&cam->unkA8);
     }
 
-    sp2C = &cam->unk64;
+    idMtx = &cam->unk64;
     if ((cam->flags & CAMERA_FLAG_CONTROLLABLE) != 0) {
         if (ctrl->btnB != FALSE && ctrl->prevFrame->btnB == FALSE) {  // new B press
             cam->zoomLevel++;
@@ -1645,7 +1638,7 @@ void move_camera(struct ObjCamera *cam) {
         cam->unk40.y += (cam->unk4C.y - cam->unk40.y) * cam->unk17C;
         cam->unk40.z += (cam->unk4C.z - cam->unk40.z) * cam->unk17C;
     } else {
-        gd_set_identity_mat4(sp2C);
+        gd_set_identity_mat4(idMtx);
     }
 
     spD4.x = cam->unk40.x;
@@ -1656,16 +1649,16 @@ void move_camera(struct ObjCamera *cam) {
     spD4.y += spB0.y;
     spD4.z += spB0.z;
 
-    gd_mult_mat4f(sp2C, &cam->unkA8, &cam->unkA8);
+    gd_mult_mat4f(idMtx, &cam->unkA8, &cam->unkA8);
     gd_mat4f_mult_vec3f(&spD4, &cam->unkA8);
 
     cam->worldPos.x = spD4.x;
     cam->worldPos.y = spD4.y;
     cam->worldPos.z = spD4.z;
 
-    cam->worldPos.x += spE0.x;
-    cam->worldPos.y += spE0.y;
-    cam->worldPos.z += spE0.z;
+    cam->worldPos.x += worldPos.x;
+    cam->worldPos.y += worldPos.y;
+    cam->worldPos.z += worldPos.z;
 }
 
 /* @ 22F7A4 for 0x38; orig name: func_80180FD4 */
@@ -1675,9 +1668,6 @@ void move_cameras_in_grp(struct ObjGroup *group) {
 
 /* @ 22F7DC for 0x36C*/
 void func_8018100C(struct ObjLight *light) {
-    Mat4f mtx;
-    UNUSED u32 pad1C[3];
-
     if (light->unk40 == 3) {
         if (light->unk30 > 0.0) { //? 0.0f
             light->unk30 -= 0.2;  //? 0.2f
@@ -1693,44 +1683,7 @@ void func_8018100C(struct ObjLight *light) {
 
         light->unk3C &= ~1;
     }
-    // if (1)?
     return;
-    // unreachable
-    light->position.x += light->unk80.x;
-    light->position.y += light->unk80.y;
-    light->position.z += light->unk80.z;
-
-    // should be position.x for second comparison?
-    if (light->position.x > 500.0f || light->position.y < -500.0f) {
-        light->unk80.x = -light->unk80.x;
-    }
-
-    if (light->position.y > 500.0f || light->position.y < -500.0f) {
-        light->unk80.y = -light->unk80.y;
-    }
-
-    if (light->position.z > 500.0f || light->position.z < -500.0f) {
-        light->unk80.z = -light->unk80.z;
-    }
-
-    return;
-    // more unreachable
-    D_801A81C0 += 1.0; //? 1.0f
-    D_801A81C4 += 0.6; //? 0.6f
-
-    gd_set_identity_mat4(&mtx);
-    gd_absrot_mat4(&mtx, GD_Y_AXIS, light->unk68.y);
-    gd_absrot_mat4(&mtx, GD_X_AXIS, light->unk68.x);
-    gd_absrot_mat4(&mtx, GD_Z_AXIS, light->unk68.z);
-    gd_mat4f_mult_vec3f(&light->unk8C, &mtx);
-
-    light->position.x = light->unk8C.x;
-    light->position.y = light->unk8C.y;
-    light->position.z = light->unk8C.z;
-    return;
-    // even more unreachable
-    gd_mat4f_mult_vec3f(&light->unk80, &mtx);
-    imout(); // this call would cause an issue if it was reachable
 }
 
 /* @ 22FB48 for 0x38; orig name: func_80181378 */