I really liked the smooth color transitions in the game. They feel very pleasant and never become distracting, which made the experience more enjoyable.
However, I think it's possible to achieve very high scores by playing at a steady pace. On my first attempt, I survived for 3 minutes and 42 seconds and scored 92k. If the game's speed gradually increased over time, it would feel more challenging, competitive, and exciting.
Other than that, the game is excellent.