It'd be tricky to do a lot for jumping since there's no delay on it, but something small would be nice =]

I guess the most that could be done is simulating that the player is moving, so the arms and legs swing like when sprinting and jumping? Not sure if jumping can be improved much.

I would try this:

1. Swing both arms up a little (like 10°) then have them move slightly back and forth repeatedly until landing.
2. Move the legs to a full stride position then freeze them there for the duration of the jump. Check if making them wave slightly works.

It's also a problem because you don't know when the jump is going to end and a landing animation would be ideal as well. Moving the character model off of his normal center and bending the knees would let you do some really slick looking things, but I'm not sure whether the skeleton you're working with allows that =]

Right now I'm just imagining the super Mario jump 🤔 But yea could look into what can be done.

The super mario jump would probably work just fine in minecraft. And it's certainly an improvement over the vanilla "vertical slide" aesthetic. Go for it =]