Changed the Reacher's brain type to Player and set the control to up, down, left, right arrows.

unity-environment/Assets/ML-Agents/Examples/Reacher/Scene.unity

   m_Name: (Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)(Clone)
   m_EditorClassIdentifier: 
   broadcast: 1
-  continuousPlayerActions: []
+  continuousPlayerActions:
+  - key: 273
+    index: 0
+    value: 1
+  - key: 274
+    index: 0
+    value: -1
+  - key: 275
+    index: 1
+    value: 1
+  - key: 276
+    index: 1
+    value: -1
   discretePlayerActions: []
   defaultAction: -1
   brain: {fileID: 846768605}
     - 
     vectorActionSpaceType: 1
     vectorObservationSpaceType: 1
-  brainType: 2
+  brainType: 0
   CoreBrains:
   - {fileID: 77695183}
   - {fileID: 1951521470}