diff --git a/TODO b/TODO
index b6feb3e..2822a8e 100644
--- a/TODO
+++ b/TODO
@@ -1,4 +1,11 @@
-- implement IImmutableComponent and ITimedComponent
+- immutable component system?
+
+- method to remove all components of a type without destroying Entities
+- method to remove a component of a type without destroying entity
+
+- auto destroy entities that no longer have components 
+
+- fast lookup for messages that contain entity references instead of `Where` loop?
 
 - look at test coverage
 - docs