I honestly only found it cause I saw you talking about it in here. Before that my strategy was to either go left or right once beside one of the goals and just mash the shoot button. Shooting things tends to preserve more momentum which can keep you bouncing longer.
For the music typically you want to make a song last for 2-3 minutes before looping. Probably even up to 5-7 if its the only track used for the game and you're going for a more ambient style. It looks like you've got an ostinato playing throughout the entire song which is nice(I tend to overuse them a bunch in my songs myself). Typically when you use an ostinato though you want to have a lot of things change about the song at different moments and take the focus away from it to make it seem like something completely new. As an example of this I've got one I the songs I composed for this jam: www.youtube.com/watch?v=7xr-gif00Ks. I've got a piano pattern playing in the background through the entire piece but it only takes the focus at different parts of the song and the rest of the time I've got something else playing to develop the piece. I've also got some slight variations on the ostinato to help it become less stale while still keeping the same general pattern. As an example of someone else using them like this, there's most of Toby Fox's songs. A good one where you can clearly hear it is bonetrousle: www.youtube.com/watch?v=AKAiUtWZ4xY
If you ever wanna talk about more things related to music feel free to message me