Thanks for the feedback~
It was really fun to work on our first Jam! We uploaded a new version with a new level and worked a bit on the camera (it should be a bit more smooth now).
About the disappearing sword, it's a mechanic that won't allow you to go too far from your hero... to kind prevent players from clearing everything ahead the time. And thanks for the tip, we can add this mechanic on a future "tutorial" (as we plan to have dialog on the game too).
Enjoy the Jam! ^.^