diff --git a/apps/demos/scenery/scenes/ingame.c b/apps/demos/scenery/scenes/ingame.c
index d944358..63e6fe1 100644
--- a/apps/demos/scenery/scenes/ingame.c
+++ b/apps/demos/scenery/scenes/ingame.c
@@ -19,7 +19,7 @@
 #define PLAYER_HEIGHT 0.6f
 #define TREE_DENSITY 0.03f
 
-#define G_CONST 0.1f
+#define G_CONST 10.0f
 
 /* TODO: pregenerate grid of levels of detail */
 static float heightmap[TERRAIN_DISTANCE][TERRAIN_DISTANCE];
@@ -58,11 +58,11 @@ static float heightmap[TERRAIN_DISTANCE][TERRAIN_DISTANCE];
 #define VEHICLE_WIDTH 1.7f
 #define VEHICLE_HEIGHT 1.3f
 /* spring constant */
-#define VEHICLE_SPRING_K 400.0f
+#define VEHICLE_SPRING_K 50000.0f
 /* damping constant */
-#define VEHICLE_SPRING_C 20.0f
-#define VEHICLE_FRICTION_S 1000000.0f
-#define VEHICLE_FRICTION_K 1000000.0f
+#define VEHICLE_SPRING_C 200.0f
+#define VEHICLE_FRICTION_S 50000.0f
+#define VEHICLE_FRICTION_K 700.0f
 
 /* initial, ideal corner positions */
 static const Vec3 vbpi[8] = {
@@ -119,7 +119,7 @@ static void process_vehicle(SceneIngame *scn) {
         Facc[i] = vec3_add(Facc[i], Fg);
 
     /* apply springs */
-    for (size_t i = 0; i < 24; ++i) {
+    for (size_t i = 0; i < 28; ++i) {
         Vec3 const p0 = vbp[vbs[i][0]];
         Vec3 const p1 = vbp[vbs[i][1]];
         Vec3 const v0 = vbv[vbs[i][0]];
@@ -140,7 +140,7 @@ static void process_vehicle(SceneIngame *scn) {
         Vec3 const p = vbp[i];
         Vec3 const v = vbv[i];
         float const h = height_at(scn, (Vec2){ p.x, p.z });
-        if (h > p.y) {
+        if (h >= p.y) {
             /* displacement force */
             Vec3 const n = normal_at(scn, (Vec2){ p.x, p.z });
             float const xn = (h - p.y) * n.y;
@@ -151,22 +151,25 @@ static void process_vehicle(SceneIngame *scn) {
             /* friction force, perpendicular to displacement */
             /* portions aligned to surface normal */
             Vec3 const vov = vec3_sub(v, vec3_scale(n, vn));
+            draw_line_3d(vbp[i], vec3_add(vbp[i], vec3_scale(vov, 3)), 1, (Color){255, 0, 0, 255});
             float const vo = vec3_length(vov);
             Vec3 const Fov = vec3_sub(Facc[i], vec3_scale(n, vec3_dot(Facc[i], n)));
             float const Fo = vec3_length(Fov);
             float const fkxn = VEHICLE_FRICTION_K * xn;
-            if (fabsf(0.0f - vo) <= 0.0001f) {
+            if (fabsf(0.0f - vo) <= 0.001f) {
                 /* cannot overcome static friction, zero force along the surface */
                 if (Fo <= VEHICLE_FRICTION_S * xn) {
-                    Facc[i] = vec3_sub(Facc[i], Fov);
+                    // Facc[i] = vec3_sub(Facc[i], Fov);
+                    Facc[i] = (Vec3){0};
                 }
                 /* apply kinematic friction */
                 else {
-                    Facc[i] = vec3_sub(Facc[i], vec3_scale(vec3_norm(Fov), fkxn));
+                    Facc[i] = vec3_sub(Fov, vec3_scale(vec3_norm(Fov), fkxn));
                 }
             /* velocity with gain along the surface will not overcome */
-            } else if (vo + (Fo / VEHICLE_MASS) * ctx.frame_duration <= fkxn * ctx.frame_duration) {
-                vbv[i] = vec3_sub(vbv[i], vov);
+            } else if (vec3_length(vec3_add(vov, vec3_scale(vec3_scale(Fov, (1.0f / VEHICLE_MASS)), ctx.frame_duration))) <= fkxn * ctx.frame_duration) {
+                // vbv[i] = vec3_sub(vbv[i], vov);
+                vbv[i] = (Vec3){0};
             } else {
                 Facc[i] = vec3_sub(Facc[i], vec3_scale(vec3_norm(vov), fkxn));
             }
@@ -175,10 +178,10 @@ static void process_vehicle(SceneIngame *scn) {
 
     /* integrate forces and velocity */
     for (size_t i = 0; i < 8; ++i) {
-        Vec3 const vd = vec3_scale(Facc[i], (1.0f / VEHICLE_MASS) * ctx.frame_duration);
+        Vec3 vd = vec3_scale(vec3_scale(Facc[i], (1.0f / VEHICLE_MASS)), ctx.frame_duration);
+        if (vec3_length(vd) <= 0.02f) vd = (Vec3){0}; /* TODO: dirty hack... */
         vbv[i] = vec3_add(vbv[i], vd);
-        vbp[i] = vec3_add(vbp[i], vbv[i]);
-        vbv[i] = vec3_scale(vbv[i], 0.99f);
+        vbp[i] = vec3_add(vbp[i], vec3_scale(vbv[i], ctx.frame_duration));
     }
 }