diff --git a/src/simulator.cc b/src/simulator.cc
index a9a30e4..1c6e1e2 100644
--- a/src/simulator.cc
+++ b/src/simulator.cc
@@ -43,17 +43,31 @@ void simulator_init() {
 
   sWorld.mStaticShapes.push_back(sGroundShape);
 
-  double restitution = 0.8;
+  double restitution = 0.5;
 
-  int num_spheres = 7;
-  for (int i = 0; i < num_spheres; i++) {
-    SimBody sphere_body = CreateSphereBody(
-        1.,
-        1.,
-        restitution,
-        Vector3d::Random() * 5.,
-        Vector3d::Zero());
-    sWorld.mBodies.push_back(sphere_body);
+  int num_bodies = 10;
+  for (int i = 0; i < num_bodies; i++) {
+    SimBody body;
+
+    bool create_sphere = i %2;
+
+    if (!create_sphere) {
+      body = CreateBoxBody(
+          1.,
+          Vector3d(2., 1., 1.),
+          restitution,
+          Vector3d::Random() * 5.,
+          Vector3d::Zero());
+    } else {
+      body = CreateSphereBody(
+          1.,
+          1.,
+          restitution,
+          Vector3d::Random() * 5.,
+          Vector3d::Zero());
+    }
+
+    sWorld.mBodies.push_back(body);
   }
 
   for (int i = 0; i < sWorld.mBodies.size(); i++) {