Brodbeck's Cold Feet

Ice coalesces in a 10ft cube within range.  Each creature in the area must succeed on a dexterity saving throw or take 2d6 cold damage and become restrained by ice. On a successful save the target takes half damage and is not restrained. 

If a creature starts their turn restrained by ice they take 1d6 cold damage. A creature may use their action to attempt to to escape and reattempt their saving throw. 

The area in which the spell is cast becomes difficult terrain. A creature may choose to use their full speed to traverse it, but must succeed on an acrobatics check against the spell DC to do so. On a failure the creature falls prone.