Just played v0.3 and the game is looking great! The artsyle is consistant througout and the sound really complimentes the atmosphere. In the beginning it would be nice to have a tutorial for movement controls and I was unaware how to move until looking at your itch page. When it comes to movement, I feel that the game needed the double jump as it was difficult to get to some platforms with a single jump, it also felt more fun doing a double jump, reminded me of Shovel Knight. For the attacking, I'd suggest going for a keyboard input rather than mouse click as it felt a little awkward going from keyboard to mouse. Watch out for the chest as well, as I managed to get stuck, but I did like the feeling of exploration to different areas trying to find collectables.
Great job and I can't wait to see the next version!