All the other comments so far are valid, but I have something else to add - did they indicate a time frame you had to have it done by, and did you use all of it? Because they may not have been looking for fast turnaround time, they may have been looking for quality.
In the future if you get something similar, you may want to ask what they're looking for (gathering requirements, you might say), and optimize accordingly. Ultimately, it may be completely unrelated, but I've had both kinds of coding tests, ones where I had an hour and had to cut corners as such, and ones where I had an entire weekend and was explicitly told to make it production quality, whatever I felt that entailed.
In the future if you get something similar, you may want to ask what they're looking for (gathering requirements, you might say), and optimize accordingly. Ultimately, it may be completely unrelated, but I've had both kinds of coding tests, ones where I had an hour and had to cut corners as such, and ones where I had an entire weekend and was explicitly told to make it production quality, whatever I felt that entailed.