So from what I have read the damage is only applied on initial cast and not sustained but rule is written below
"Failure The target takes full damage, and takes a –5-foot circumstance penalty to its Speeds until the spell ends.
Critical Failure The target takes double damage and a –10-foot circumstance penalty to its Speeds until the spell ends."
Notice on Critical Failure they intentionally removed the coma after the word damage grouping the 2 subjects. They also removed the verb takes reinforcing that grouping as single entity. So does that mean the target sustain double damage until the end of the spell on Critical Failure? If not why did they not simply write it like below...
"Failure The target takes full damage and until the spell ends the targets takes a –5-foot circumstance penalty to its Speeds.
Critical Failure The target takes double damage and until the spell ends the targets takes a –10-foot circumstance penalty to its Speeds."
They really need to get a new editor.