Since levels can now be adjusted to less than 360x120 pixels, it can now potentially be harder to tell where the side of the level is deadly, especially if the small level does not have any walls and there is no background in the level.
I suggest that indicators of deadly sides be included in Clear Physics mode, which will also help players have a better idea of how small the level is. Attached is a picture below to see what the indicators can look like (though there can be better suggestions than this); this level's size is 150x160 pixels.
Added for next update.