Function Points (FP) method has been trusty and proven to be effective to estimate the effort of thousands of software development projects. Nowadays, the mobile game development-especially in a casual genre-is growing. Therefore, the researcher is excited to test the FP method whether it can also be applied to estimating the game development effort. FP method usually consists of 3 main stages: weighing 5 parameters of Unadjusted FP, calculating 14 complexity factors, and calculating Adjusted FP. Survey to 8 casual games was conducted and the value of effort for each one of them has been estimated. So, we conclude that FP is not suitable to forecast the effort of mobile casual games. There are 376 percent deviation between effort estimations and actual effort. The authors suspect, for mobile game development, the game's point of view needs to be re-adjusted to 5 input parameters, complexity factors, conversion of programming languages, and productivity rate.