Glad to help how I can. Doing game jams I've been playing a lot more styles of games than I normally would. These days I do a lot more turn-based than fast paced, but I used to do more real-time.
I'm really not sure on the boost issue. I tried to test it more, but the game was challenging and I was not able to figure out a good way to test. I tried both in the tutorial and main game. I'm not sure if the tutorial limits when it becomes enabled, as I was not able to use it at the start when I had the issue, but playing through it again I did eventually get it to work. Since I wasn't sure on the tutorial, my main testing was to start a new game and immediately try to use the boost and barrel roll. I'd press and hold for boost, but nothing happened. I was not loosing energy. I did not see any visual, or hear any audio, indication it was working. Trying the barrel roll I can acknowledge that I didn't always time things right to trigger it, but I retried it several times and similarly never saw it happen. After a restart it seemed to be working. I know this isn't that helpful, because I really don't have any key details to narrow it down. I even opened up a doc and started typing to make sure my keyboard was still working correctly. One thought I had was maybe something to do with the Caps Lock key, as I did accidentally press it at one point, but toggling it didn't seem to have any impact. The biggest issue is that I was trying to learn so much at once and my attention so spread, that when it first started to be an issue I figured I made a mistake, but didn't really pay enough attention to what was happening right away. I don't know if it was tied to boosting or doing a barrel roll when I died or perhaps activated a shop. There are many things I could see it being, but my skill was not sufficient to retest. The best I can say is that it seemed to happen at some point as I played and restarting the game seemed to fix it. When I next play I will try to pay more attention for if/when it happens and what may have happened before it.