Press space or tap the screen to damage the (invisible) boss. Press R to refill the health bar (doesn't always work)
v2: https://scratch.mit.edu/projects/1183304103/ v3: https://scratch.mit.edu/projects/1197634281/ Recreation of that cool looking 3d health bar that appears when you fight a boss in Klonoa 2. I have no idea on what to use this in, so I'm just uploading this here for anyone to use. Music used: "Beats from Above" from Klonoa: Door to Phantomile