diff --git a/reasoning_gym/arithmetic/chain_sum.py b/reasoning_gym/arithmetic/chain_sum.py
index e9a02d66..24afda1a 100644
--- a/reasoning_gym/arithmetic/chain_sum.py
+++ b/reasoning_gym/arithmetic/chain_sum.py
@@ -19,7 +19,6 @@ class ChainSumConfig:
 
     def validate(self) -> None:
         """Validate configuration parameters"""
-        assert self.difficulty > 0, "difficulty must be positive"
         assert self.size > 0, "size must be positive"
         """Validate configuration parameters"""
         assert self.min_terms > 0, "min_terms must be positive"
diff --git a/reasoning_gym/cognition/rubiks_cube.py b/reasoning_gym/cognition/rubiks_cube.py
index 264eef46..f504d92d 100644
--- a/reasoning_gym/cognition/rubiks_cube.py
+++ b/reasoning_gym/cognition/rubiks_cube.py
@@ -15,6 +15,7 @@ class RubiksCubeConfig:
 
     scramble_steps: int = 3  # Number of random steps from initial state
     cube_size: int = 3  # Default to a standard 3x3x3 cube
+    remove_ansi: bool = True
     seed: Optional[int] = None
     size: int = 500
 
@@ -78,7 +79,12 @@ class RubiksCubeDataset(ProceduralDataset):
         cube = Cube(self.config.cube_size)
         scramble_moves = self._generate_random_moves(rng, cube, num_steps=self.config.scramble_steps)
         cube.rotate(scramble_moves)
-        cube_render = self.remove_ansi(str(cube))
+
+        # render cube
+        if self.config.remove_ansi:
+            cube_render = self.remove_ansi(str(cube))
+        else:
+            cube_render = str(cube)
 
         if self.config.cube_size == 3:
             solver = BasicSolver(cube)
@@ -102,10 +108,8 @@ class RubiksCubeDataset(ProceduralDataset):
 
     def score_answer(self, answer: Optional[str], entry: Dict[str, any]) -> float:
         """Determine if the solution provided solves the cube"""
-        answer = answer.strip()
-
-        reward = 0.0
-        if answer is not None and len(answer) > 0:
+        reward = 0.0  # default reward
+        if answer is not None:
             # Reconstruct the test cube
             eval_cube = Cube(entry["metadata"]["cube_size"])
             eval_cube.rotate(entry["metadata"]["scramble_moves"])
@@ -117,8 +121,10 @@ class RubiksCubeDataset(ProceduralDataset):
 
                 if solved:
                     reward = 1.0
+                elif len(answer.strip()) > 0:  # encourage non-empty answers
+                    reward = 0.05  # Incorrect, but rotate could parse the answer
                 else:
-                    reward = 0.1  # Incorrect, but rotate could parse the answer
+                    reward = 0.01
             except:
                 reward = 0.01  # At least you tried
 
diff --git a/tests/test_rubiks_cube.py b/tests/test_rubiks_cube.py
index 96e7d41d..781d2e69 100644
--- a/tests/test_rubiks_cube.py
+++ b/tests/test_rubiks_cube.py
@@ -49,5 +49,11 @@ def test_rubikscube_items():
         assert "example_correct_answer" in item["metadata"]
 
         assert dataset.score_answer(answer=item["metadata"]["example_correct_answer"], entry=item) == 1.0
-        assert dataset.score_answer(answer="R", entry=item) == 0.01
+        assert dataset.score_answer(answer="a wrong solution", entry=item) == 0.01
         assert dataset.score_answer(answer=None, entry=item) == 0.0
+
+        if item["metadata"]["example_correct_answer"] != "R":
+            assert dataset.score_answer(answer="R", entry=item) == 0.05
+
+        if len(item["metadata"]["example_correct_answer"]) > 0:
+            assert dataset.score_answer(answer="", entry=item) == 0.01