Cool metroidvania styled game, I was quite excited to hunt down the items however I found the respawn mechanic to be a little bit unintuitive. There's a lot of punishment for exploring and trying new things. If I've managed to gather some upgrades and then I think "I can probably make this jump now" and I screw it up, having to restart from scratch hurts. I understand though that your looping mechanic relies on the return to the bird cage to remain alive and stash the items for the future. Often though I'd die to other threats before my health would drain enough to be an issue and that was a hard restart.
The movement felt smooth though! And jumping around, especially the triple jump, felt like it gave enough air control that you could do a lot with it. I also love a good set of hidden breakable walls slightly out of the way and the desire to explore far enough to see what's beyond them. Nice work!