A quite fun little platformer! I had a fun time playing it through! You can check out the VOD of my playthrough here if you're interested.
I agree some of the spike hitboxes felt punishing, and the jump had a hard time registering on the vertically moving platform/pillar where a little bit of "coyote time" might have helped it feel a little smoother. But honestly, those are just small nitpicks! Great job, especially solo. It felt like a really complete experience!