Really nice submission! It always feels good to jump on enemies, and I think you did a great job with this classical genre. Also, I appreciated that the sections of the path have a clear level design: it's easy to understand what the player is supposed to do and how, and that avoids moments of frustration.
The only part where this is missing is on the five sequential clouds (where I remained stuck...). It's clear what to do, but not how to do it, because the movement of the clouds cannot be traced from the player perspective. This means that, by adding just a few reference elements in the air path, things should become easier and your strong mechanics could emerge as deserved :)
Besides that, congratulations for your great job! Considering it's your first AND it's in 3D AND it's really enjoyable, you should be proud :D