diff --git a/README.md b/README.md
index c8f824b..4db68a0 100644
--- a/README.md
+++ b/README.md
@@ -37,9 +37,11 @@ some more practical uses would be things like:
 
 ## todo
 
-* implement Result return types on ::from functions so we can handle errors
+* implement Result return types on ::from functions so that we can handle errors
 * replace Image with Vec<u8> or something. seems like a pointless abstraction
 * replace game avatar with helper functions to get and set the sprite with an ID of A
+* implement PartialEq for tiles etc. for the sake of checking for duplicate tiles?
+* dedupe functions for tiles, sprites, etc.
 
 ### tidy up
 
diff --git a/src/game.rs b/src/game.rs
index 8254756..c8b8818 100644
--- a/src/game.rs
+++ b/src/game.rs
@@ -106,7 +106,7 @@ pub struct Game {
 
 #[derive(Debug)]
 pub struct GameHasNoAvatar;
-// todo no tiles? no rooms? no palettes?
+// todo no tiles? no rooms? no palettes? turn this into an enum?
 
 impl Game {
     #[inline]
@@ -376,6 +376,8 @@ impl Game {
         self.items.iter().map(|item| item.id.clone()).collect()
     }
 
+    // todo dedupe?
+
     /// first available tile ID.
     /// e.g. if current tile IDs are [0, 2, 3] the result will be `1`
     ///      if current tile IDs are [0, 1, 2] the result will be `3`