"Going to town on" typically refers to doing something with enthusiasm or fervor. Some antonyms for this phrase could include "half-hearted," "apathetic," "lackadaisical," "unenthusiastic," or "indifferent." Each of these words suggests a lack of passion or energy in one's approach to a given task or activity. For example, when someone is "going to town on" a project or assignment, they're putting all of their effort into it and working diligently. On the other hand, if someone is "half-hearted" about a task, they may complete it, but without passion or urgency. By using antonyms to "going to town on," we can better understand the degree to which someone is invested in a particular task or activity.