Answer: Karma and līlā are as different as heaven and hell. Karma is performed with material senses, which are bahirmukha, or directed away from service to Kṛṣṇa, whereas līlā is realized through transcendental senses, which are perfectly suited for serving Kṛṣṇa.
The material world is the place of karma, and our gross and subtle designations are its basis. Karma is temporary, while līlā is eternal. Karma is the suffering we undergo on account of the three forms of misery, or the punishment given to the conditioned souls, but līlā is the blissful pastimes manifest by the completely independent sweet will of the supremely autocratic Personality of Godhead, Puruṣottama.
The realm for līlā, however, is Vaikuṇṭha, or Goloka, which is beyond the fourteen planetary systems of this material universe, beyond the Virajā, and even beyond brahma-loka. By the desire of the Supreme Lord, who is līlā-maya, or richly imbued with pastimes, līlā manifests within this world through His līlā potency. However, by its very nature, līlā is beyond the reach of the material senses (atindriya) and even beyond anything the material mind can conceive (avicintya). It is never tainted by anything mundane, nor is it subordinate to anything mundane. This is the sole verdict of gauḍīya darśana (the philosophical revelations of the Gauḍīya Vaiṣṇavas, who are the followers of Śrī Caitanya Mahāprabhu).
from Śrīla Prabhupādera Upadeśāmṛta
Śrīla Prabhupādera Upadeśāmṛta is a compilation of Śrīla Bhaktisiddhānta Sarasvatī Ṭhākura Prabhupāda’s instructions in question-and-answer form.