Open Signal is a clean and well-executed level by Zhenstar. Starting off with the gameplay, it surprisingly has great progression for a 4*, both in relation to the song and difficulty of the level. The effects used in the first part really well capture the rising part of the song, and the effects used throughout (though some subtle) really add to the song representation here. The colors used look really good, and the gameplay is intuitive with not much handholding. I personally think this would have been a good candidate for an epic rating as it utilizes the song and colors and effects well. I particularly like the wave part and the upside-down cube part as they are the most visually interesting, and the small details used tie well together. I do wish this was either a bit longer or had slightly more variation in designs, and the swingcopter part is slightly empty. I think some sort of ground designs would have filled in that empty space. Regardless, this is a great level from zhen and I hope to see more like this in the future.