Hey, there are some bugs when entering into slide mode (X) and using a stick to move the blocks around:
I managed to slide away one of the pieces so it was no longer in the bounding box of the level.
More:
Additionally in the settings menu the marker for the highlighted element is almost invisible on most options and competely invisible on the resolution select: 
And the dropdown has multiple entries for the same resolution (probably with different hz) and doesn't scroll down as you go through the elements.