Back to my psychic monk!

Mind Grab Spell 1

Concentrate mental
Traditions occult
Cast [two-actions]
Range touch 
Defense Will; Duration sustained up to 1 minute

---

You reach out and grab a creature lightly and your mental force grabs the creature. The target must attempt a Will save. Each turn you can Sustain this spell and the target is still immobilized takes 2d6 bludgeoning damage. A creature can attempt to Escape, rolling against your spell DC.

Success The creature is unaffected.
Failure The creature is immobilized and takes 2d6 bludgeoning damage.
Critical Failure The creature is immobilized and take 4d6 bludgeoning damage.

---

Heightened (+1) The bludgeoning damage dealt when you Sustain this spell increases by 1d6 and 2d6 for creatures who fail who critically fail the saving throw.

What do you think ? Damage too high for level 1 spell or does having to be damager close compensate?