The phrase "go to town on" often means to do something with great enthusiasm or to put a lot of effort into it. However, there are several antonyms for this phrase, which convey the opposite meaning. Some of these antonyms include "halfheartedly," "sluggishly," "lazily," and "unenthusiastically." If you want to emphasize the lack of effort put into something, you could use phrases like "half-assed," "minimal effort," or even "phoning it in." The antonyms of "go to town on" are useful when you want to convey that someone is not putting in their best effort, or that they are not fully invested in a task.