diff --git a/src/engine.ts b/src/engine.ts
index 59e2fe3..62e6ded 100644
--- a/src/engine.ts
+++ b/src/engine.ts
@@ -73,7 +73,7 @@ export async function startEngine(
     const { scene, floorMeshes } = await createScene(canvas, engine);
 
     const xr = await scene.createDefaultXRExperienceAsync({});
-    const xrAvailable = xr.baseExperience !== void 0;
+    const xrAvailable = xr?.baseExperience !== void 0;
 
     let camera: FreeCamera;
     if (xrAvailable) {
@@ -120,20 +120,22 @@ export async function startEngine(
 
         for (const gp of Array.from(navigator.getGamepads())) {
             if (gp !== null) {
-                const pos = new Vector3((gp.axes[0]), (-gp.axes[1]), (-gp.axes[3]));
-                if (pos.length() > 0.0625) {
-                    if (leanBase === null) {
-                        leanBase = { position: xr.baseExperience.camera.position };
+                if (sm) {
+                    const pos = new Vector3((gp.axes[0]), (-gp.axes[1]), (-gp.axes[3]));
+                    if (pos.length() > 0.0625) {
+                        if (leanBase === null) {
+                            leanBase = { position: xr.baseExperience.camera.position };
+                        }
+                        xr.baseExperience.camera.position =
+                            pos.applyRotationQuaternion(xr.baseExperience.camera.absoluteRotation)
+                                .scale(0.25)
+                                .add(leanBase.position);
+                    } else {
+                        if (leanBase !== null) {
+                            xr.baseExperience.camera.position = leanBase.position;
+                        }
+                        leanBase = null;
                     }
-                    xr.baseExperience.camera.position =
-                        pos.applyRotationQuaternion(xr.baseExperience.camera.absoluteRotation)
-                            .scale(0.25)
-                            .add(leanBase.position);
-                } else {
-                    if (leanBase !== null) {
-                        xr.baseExperience.camera.position = leanBase.position;
-                    }
-                    leanBase = null;
                 }
 
                 if (sm && latch(gp, 0)) {
@@ -158,12 +160,18 @@ export async function startEngine(
                 if (sm && latch(gp, 3)) {
                     enableVR();
                 }
-                if (sm && latch(gp, 5)) {
-                    const q = xr.baseExperience.camera.rotationQuaternion;
-                    const r = q.toEulerAngles();
+                if (latch(gp, 5)) {
+                    const r = sm
+                        ? xr.baseExperience.camera.rotationQuaternion.toEulerAngles()
+                        : camera.rotation;
                     r.y += Math.PI;
                     r.y %= 2 * Math.PI;
-                    q.copyFrom(Quaternion.FromEulerAngles(r.x, r.y, r.z));
+                    if (sm) {
+                        xr.baseExperience.camera.rotationQuaternion.copyFrom(r.toQuaternion());
+                    }
+                }
+                if (sm && latch(gp, 4)) {
+                    xr.baseExperience.camera.rotationQuaternion.copyFrom(initialRotation.toQuaternion());
                 }
             }
         }