Sound Horizons is a free, straightforward,and minimalist music game where the players are given musical notes that they must react to accordingly using a circular panel divided into four sections as they fly into the horizon. This allows them to generate unique melodies to survive until the end. 

Interact with unpredictable musical patterns 

Sound Horizons offers a simple, abstract playthrough that relies on music interactivity for music-based procedural generation. This means melodies are always random, giving players unpredictable music patterns that spice up the gameplay. In addition, it also has a procedural landscape that matches the beat for synesthetic purposes. 

Due to its music-based procedural generation aspect, this game has an adaptive difficulty, reassuring players that the difficulty matches their skills. It also contains additional modes for challenges and experience. However, the game's premise allows for repetitive elements, making it tedious after some time. 

Musical title for killing time 

Sound Horizons is a fun and simple game perfect for killing time. With its music-based procedural generation, procedural landscape, and adaptive difficulty aspects, the game provides players with unpredictable yet doable gameplay. However, due to its repetitive element, it gets tedious after a while.