I really like the idea of this game. I find the concept of only being able to move while jumping to be a very interesting game mechanic idea! Unfortunately, for me, the actual movement controls are very difficult to get to grips with. The use of acceleration makes the character feel like they’re moving way too slow when starting out, then, after a successful jump or two, feels like they’re going way too fast. In the latter case, trying to correct for how fast I’m moving felt very unresponsive. There’s nothing wrong with accelerating up or down, but it needs some significant adjustment as it is now. I’m thinking movement should be at least as responsive as in the classic Mario games.
Another issue I had was the placement of tutorial text. Over all, I thought the text worked well as an element in the world, but where it was placed was often awkward at best. One I had a particular issue with was at the start of the first level, if you fall to the ground where the dog/beaver/wolverine animal thing was, there’s text that, I think, says something to the effect of “beware of dog”, but I’m not quite sure as I was never able to get close enough to read it.
Like I said, I love the idea of the mechanic, but the controls did not feel like the right kind of responsive for the type of platformer game I think you were going for.