I like the concept of this game! The retro visuals are nice and the music is great. I also like seeing the ball bounce around quickly when traveling at a high speed. However, more interactive sound effects (hit, bounce) could be added to immerse the player further. Additionally, since you're using Godot, you can use a NinePatchRect node for the arrow so that as it scales, each pixel remains the same size.
Overall, this is a really good game and an amazing start for your first jam!