diff --git a/engine/camera.go b/engine/camera.go
index 2f053f5..66022bb 100644
--- a/engine/camera.go
+++ b/engine/camera.go
@@ -40,8 +40,7 @@ func (c *Camera) Prepare(game *Game) error {
 }
 
 // Transform returns the camera transform.
-func (c *Camera) Transform() ebiten.DrawImageOptions {
-	var opts ebiten.DrawImageOptions
+func (c *Camera) Transform() (opts ebiten.DrawImageOptions) {
 	opts.GeoM.Translate(float2(c.Centre.Mul(-1)))
 	opts.GeoM.Scale(c.Zoom, c.Zoom)
 	opts.GeoM.Rotate(c.Rotation)
diff --git a/engine/walls.go b/engine/walls.go
index 4a1ec51..4660e05 100644
--- a/engine/walls.go
+++ b/engine/walls.go
@@ -25,7 +25,7 @@ var (
 
 // Wall is a more flexible kind of tilemap. WallUnits can be added at the same
 // level as other components and are responsible for their own drawing, so that
-// Scene can do draw ordering, e.g. hide the player character behind a wall.
+// Game can do draw ordering, e.g. hide the player character behind a wall.
 // But Wall is still responsible for collisions.
 type Wall struct {
 	ID