Thanks for the feedback. Sorry, I didn't get to upload the UI friendly version before cutoff time. The radial slider is the tug strength. While reeling in it increases; when the bar turns yellow, it decreases the line strength (shown on the right), and if you keep reeling in until it reaches red then it decreases the line strength even faster.
So there are 2 ways the line can be snapped, tugging too hard, or having too much tension on the line for too long.