diff --git a/code/game/src/debug_ui_actions.c b/code/game/src/debug_ui_actions.c
index a8ac6be..a7bd552 100644
--- a/code/game/src/debug_ui_actions.c
+++ b/code/game/src/debug_ui_actions.c
@@ -85,6 +85,7 @@ ActEraseWorldChanges(void) {
             
             if (l.is_outer && l.block_id > 0) {
                 asset_id item_asset = blocks_get_asset(l.block_id);
+                if (item_asset == ASSET_INVALID) continue;
                 uint64_t e = item_spawn(item_asset, 1);
                 
                 Position *dest = ecs_get_mut(world_ecs(), e, Position, NULL);
diff --git a/code/game/src/gui/build_mode.c b/code/game/src/gui/build_mode.c
index 90d2099..6071ae2 100644
--- a/code/game/src/gui/build_mode.c
+++ b/code/game/src/gui/build_mode.c
@@ -1,9 +1,6 @@
 #include "camera.h"
 #include "item_placement.h"
 
-#define ZPL_ENABLE_MATH
-#include "zpl.h"
-
 static bool build_submit_placements = false;
 static bool build_is_in_draw_mode = false;
 static uint8_t build_num_placements = 0;
@@ -69,10 +66,10 @@ void buildmode_draw(void) {
                             float p2y = build_placements[1].y;
                             float p3x = (float)cam.x;
                             float p3y = (float)cam.y;
-                            float sx = zpl_sign(p2x-p1x);
-                            float sy = zpl_sign(p2y-p1y);
-                            float sxx = zpl_sign(p3x-p1x);
-                            float syy = zpl_sign(p3y-p1y);
+                            float sx = zpl_sign0(p2x-p1x);
+                            float sy = zpl_sign0(p2y-p1y);
+                            float sxx = zpl_sign0(p3x-p1x);
+                            float syy = zpl_sign0(p3y-p1y);
                             
                             if (sx != sxx || sy != syy) break;
                         }
@@ -103,6 +100,7 @@ void buildmode_draw(void) {
     if (build_is_in_draw_mode) {
         if (IsKeyPressed(KEY_SPACE)) {
             build_is_in_draw_mode = false;
+            buildmode_clear_buffers();
         }
         
         if (IsMouseButtonReleased(MOUSE_RIGHT_BUTTON)) {
diff --git a/code/game/src/items.c b/code/game/src/items.c
index 04fdf32..9870864 100644
--- a/code/game/src/items.c
+++ b/code/game/src/items.c
@@ -43,7 +43,6 @@ uint16_t item_find(asset_id kind) {
             return item_resolve_proxy(i);
     }
     
-    ZPL_PANIC("Unknown asset id: %d\n", kind);
     return ASSET_INVALID;
 }
 
diff --git a/code/game/src/world/blocks_list.c b/code/game/src/world/blocks_list.c
index 63f54e0..716a1ee 100644
--- a/code/game/src/world/blocks_list.c
+++ b/code/game/src/world/blocks_list.c
@@ -18,8 +18,8 @@ static block blocks[] = {
     BLOCK(ASSET_WOOD, BLOCK_FLAG_COLLISION, '#', .drag = 1.0f , .friction = 1.0f, .bounce = 0.0f),
     BLOCK(ASSET_TREE, BLOCK_FLAG_COLLISION, '@', .drag = 1.0f , .friction = 1.0f, .bounce = 0.0f),
     
-    BLOCK(ASSET_BELT_LEFT, 0, '@', .drag = 1.0f , .friction = 1.0f, .velx = -120.0f),
-    BLOCK(ASSET_BELT_RIGHT, 0, '@', .drag = 1.0f , .friction = 1.0f, .velx = 120.0f),
-    BLOCK(ASSET_BELT_UP, 0, '@', .drag = 1.0f , .friction = 1.0f, .vely = -120.0f),
-    BLOCK(ASSET_BELT_DOWN, 0, '@', .drag = 1.0f , .friction = 1.0f, .vely = 120.0f),
+    BLOCK(ASSET_BELT_LEFT, 0, '@', .drag = 1.0f , .friction = 1.0f, .velx = -150.0f),
+    BLOCK(ASSET_BELT_RIGHT, 0, '@', .drag = 1.0f , .friction = 1.0f, .velx = 150.0f),
+    BLOCK(ASSET_BELT_UP, 0, '@', .drag = 1.0f , .friction = 1.0f, .vely = -150.0f),
+    BLOCK(ASSET_BELT_DOWN, 0, '@', .drag = 1.0f , .friction = 1.0f, .vely = 150.0f),
 };
diff --git a/code/modules/source/system_items.c b/code/modules/source/system_items.c
index e8d3cea..afb20e7 100644
--- a/code/modules/source/system_items.c
+++ b/code/modules/source/system_items.c
@@ -204,8 +204,8 @@ void UseItem(ecs_iter_t *it) {
                 float p1y = in[i].placements_y[0];
                 float p2x = in[i].placements_x[1];
                 float p2y = in[i].placements_y[1];
-                float sx = zpl_sign(p2x-p1x);
-                float sy = zpl_sign(p2y-p1y);
+                float sx = zpl_sign0(p2x-p1x);
+                float sy = zpl_sign0(p2y-p1y);
                 ofs = (sx < 0.0f) ? 1 : 2;
                 if (sx == 0.0f) {
                     ofs = (sy < 0.0f) ? 3 : 4;
diff --git a/code/vendors/zpl.h b/code/vendors/zpl.h
index 35eaf09..5a23e69 100644
--- a/code/vendors/zpl.h
+++ b/code/vendors/zpl.h
@@ -31,6 +31,7 @@ GitHub:
   https://github.com/zpl-c/zpl
 
 Version History:
+  15.0.2  - zpl_sign0 was introduced
   15.0.1  - hashtable performance improvements
   		- zpl_sign(0) returns 0
   15.0.0  - Rework zpl ring buffer
@@ -4415,7 +4416,6 @@ return NULL;
 }                                                                                                                  \
 \
 void ZPL_JOIN2(FUNC, remove)(NAME * h, zpl_u64 key) {                                                                  \
-zpl_isize i; \
 zpl_hash_table_find_result fr = ZPL_JOIN2(FUNC, _find)(h, key);                                                \
 if (fr.entry_index >= 0) {                                                                                     \
 zpl_array_remove_at(h->entries, fr.entry_index);                                                           \
@@ -6595,7 +6595,11 @@ typedef short zpl_half;
 #endif
 
 #ifndef zpl_sign
-#define zpl_sign(x) (x == 0.0f) ? 0.0f : ((x) >= 0.0f ? 1.0f : -1.0f)
+#define zpl_sign(x) ((x) >= 0.0f ? 1.0f : -1.0f)
+#endif
+
+#ifndef zpl_sign0
+#define zpl_sign0(x) ((x == 0.0f) ? 0.0f : ((x) >= 0.0f ? 1.0f : -1.0f))
 #endif
 
 ZPL_DEF zpl_f32 zpl_to_radians(zpl_f32 degrees);
@@ -18171,9 +18175,4 @@ typedef zpl_intptr intptr;
 // source/core/print.c
 // source/core/time.c
 // source/core/string.c
-// source/core/random.c
-// source/core/sort.c
-// source/core/file_tar.c
-// source/opts.c
-// source/timer.c
-// source/math.c
+// source/c
\ No newline at end of file