Try downloading it again, I just reuploaded the zip file with a new version with some performance improvements (still listed as v1.0).
If it's still stuttery for you even with the performance improvements, you can also try opening the config.txt file and increasing the number for the syncTime. (Explanation: the syncTime is the maximum number of frames the music is allowed to be out of sync with the visuals, so if your game consistently lags behind by more than that amount the music will keep stuttering trying to resync itself (default value is 4 frames = 1/15th of a second). So increasing this number allows your editor more room to lag before triggering an audio resync, at the expense of also allowing more room for the music to be out of sync)