I enjoyed this game, I liked the long tutorial building up to the core gameplay arena, I wasn't expecting that and it worked super well. Smashing into enemies and spikes felt super good, especially with the dissolve animation you had on them.
If you wanted to improve, I suggest making the boost meter more visible. I couldn't see it on most stages and even when I could, it was hard to tell what meant what. I suggest removing the bar and just adding a particle effect to the player when they can boost. I also recommend adding just a touch of screen shake to drive home the impact of boosting into something.
Overall, quality project!