To add to the 'Dash Freeze' glitch I just wanted to say that the NG Medals for completing a stage with full HP don't work either. Just to be precise, I have only completed the first stage with full HP and so I cannot give you a bug report with Stage 2 & 3.
Otherwise, would've a little more fun as a side-scroller than just fighting a 3 stage boss, which one ends up grinding to buy everything from the imaginary shop.