In this paper we present our research in the area of authoring tools development. The over arching goal of this work is to provide mechanisms that can be used to measure the design characteristics of games. We aim to develop a framework that can offer designers ongoing informative feedback on the difficulty of a level as they build prototypes, thus allowing them to gauge their designs. We outline a number of measures, which we hypothesise can be useful in predicting the difficulty of a level. In this work we present details of our exemplar game, and the reasons for choosing it as our test bed. We incorporate a naive strategy for simulating a player's performance in any given instance of this game. In order to verify the usefulness of our measures, we undertake an extensive set of experiments using this simulated player. We present the results illustrating the relationship between our measures and the performance of the simulated player.