diff --git a/engine/asset.go b/engine/asset.go
index 1c7ee4b..4a2bfb8 100644
--- a/engine/asset.go
+++ b/engine/asset.go
@@ -12,6 +12,7 @@ import (
 var (
 	// AnimDefs are easier to write as Go expressions -
 	// so just set this.
+	// TODO: put in Game
 	AnimDefs map[string]*AnimDef
 
 	imageCache = make(map[string]*ebiten.Image)