diff --git a/app_file.c b/app_file.c
index 7961f49..080849f 100644
--- a/app_file.c
+++ b/app_file.c
@@ -214,12 +214,9 @@ static void _app_LevelCommand(App *app, char *cmd) {
 }
 
 
-// Defined in render_bundle_file.c
-extern char linebuf[512];
-
 void _app_SwitchLevel(App *app) {
 	if (app->switch_level == NULL) {
-		WARN("called when switch_level is NULL", 0);
+		WARN("called when switch_level is NULL");
 		return;
 	}
 	INFO("Switching level to %s", app->switch_level);
@@ -238,6 +235,8 @@ void _app_SwitchLevel(App *app) {
 	app->camera->target = NULL;
 
 	// Read every line
+	char linebuf[512];
+	memset(linebuf, 0, sizeof(linebuf));
 	while (!feof(f) && fgets(linebuf, sizeof(linebuf), f)) {
 		while (linebuf[strlen(linebuf) - 1] == '\n')
 			linebuf[strlen(linebuf) - 1] = '\0';
diff --git a/physics.c b/physics.c
index ab6e970..195931b 100644
--- a/physics.c
+++ b/physics.c
@@ -86,7 +86,7 @@ static inline void _physics_AdvanceEntity(System_Physics *sys, Entity *e, Durati
 }
 
 
-static double gravity = 2000;
+static const double gravity = 2000;
 
 void physics_Advance(System_Physics *sys, Duration deltaTime) {
 	for (tree_Node *i = tree_FirstNode(sys->pos);
diff --git a/player.c b/player.c
index c8fdfe1..8cda913 100644
--- a/player.c
+++ b/player.c
@@ -56,9 +56,9 @@ void player_DeleteEntity(System_Player *sys, uintptr_t id) {
 }
 
 
-static double   walkSpeed = 300.0, jumpSpeed = 800.0, dashSpeed = 1500.0;
-static int      airjumpCount = 1, airdashCount = 1, airjumpParticleCount = 10;
-static Duration dashLength = {.microseconds = 150000}, dashCooldown = {.microseconds = 400000};
+static const double   walkSpeed = 300.0, jumpSpeed = 800.0, dashSpeed = 1500.0;
+static const int      airjumpCount = 1, airdashCount = 1, airjumpParticleCount = 10;
+static const Duration dashLength = {.microseconds = 150000}, dashCooldown = {.microseconds = 400000};
 
 
 void player_Advance(System_Player *sys, Duration deltaTime) {
@@ -179,7 +179,7 @@ void player_Advance(System_Player *sys, Duration deltaTime) {
 }
 
 
-static int harmed_particle_count = 20;
+static const int harmed_particle_count = 20;
 
 void player_HazardHarm(System_Player *sys) {
 	if (!sys->player)
diff --git a/render_bundle_file.c b/render_bundle_file.c
index a26c255..ad4a74b 100644
--- a/render_bundle_file.c
+++ b/render_bundle_file.c
@@ -25,7 +25,7 @@ static void _render_BundleCommand(char *cmd) {
 	if (CMD("BUNDLE")) {
 		// Start a bundle
 		if (_tmpb != NULL) {
-			WARN("_tmpb!=0, you forgot to use ENDBUNDLE for the last bundle, discarding", 0);
+			WARN("_tmpb!=0, you forgot to use ENDBUNDLE for the last bundle, discarding");
 			free(_tmpb);
 		}
 		_tmpb = render_NewBundle(strtok(NULL, " "));
@@ -38,13 +38,13 @@ static void _render_BundleCommand(char *cmd) {
 			vector_Push(render_Bundles, &_tmpb);
 			_tmpb = NULL;
 		} else
-			WARN("_tmpb==0, ENDBUNDLE without BUNDLE first", 0);
+			WARN("_tmpb==0, ENDBUNDLE without BUNDLE first");
 
 
 	} else if (CMD("PRIM")) {
 		// start a primitive
 		if (_tmpp != NULL) {
-			WARN("_tmpp!=0, you forgot to ENDPRIM for the last primitive, discarding", 0);
+			WARN("_tmpp!=0, you forgot to ENDPRIM for the last primitive, discarding");
 			if (_tmpp->points)
 				vector_Destroy(_tmpp->points);
 			free(_tmpp);
@@ -82,7 +82,7 @@ static void _render_BundleCommand(char *cmd) {
 			Vec2   v = vec2(x, y);
 			vector_Push(_tmpp->points, &v);
 		} else
-			WARN("P without PRIM first", 0);
+			WARN("P without PRIM first");
 	} else if (CMD("FG")) {
 		// Set Foreground color
 		if (_tmpp) {
@@ -91,7 +91,7 @@ static void _render_BundleCommand(char *cmd) {
 			int b          = atoi(strtok(NULL, " "));
 			_tmpp->mode.fg = RGB(r, g, b);
 		} else
-			WARN("FG without PRIM first", 0);
+			WARN("FG without PRIM first");
 	} else if (CMD("BG")) {
 		// Set Background color
 		if (_tmpp) {
@@ -100,7 +100,7 @@ static void _render_BundleCommand(char *cmd) {
 			int b          = atoi(strtok(NULL, " "));
 			_tmpp->mode.bg = RGB(r, g, b);
 		} else
-			WARN("BG without PRIM first", 0);
+			WARN("BG without PRIM first");
 	} else {
 		WARN("unknown command %s", cmd);
 	}
@@ -108,8 +108,6 @@ static void _render_BundleCommand(char *cmd) {
 }
 
 
-char linebuf[512];
-
 void render_LoadBundle(const char *filename) {
 	if (!render_Bundles)
 		render_Bundles = vector_Create(sizeof(render_Bundle *));
@@ -120,6 +118,7 @@ void render_LoadBundle(const char *filename) {
 		return;
 	}
 
+	char linebuf[512];
 	while (!feof(f) && fgets(linebuf, sizeof(linebuf), f)) {
 		while (linebuf[strlen(linebuf) - 1] == '\n')
 			linebuf[strlen(linebuf) - 1] = '\0';