First, my suggestion: Highlight the Computer's most recent line placed

Now, my reasoning:

I spent a fair amount of time working on this achievement before the timer got extended and decided to give it a go again afterward. The AI's most recent line placed was a struggle to distinguish all the time due to the weather effects, the brightness and contrast of the area, the similarity to other lines, and the fact that there is 0 indication of where the line is placed. I ended up using a trick where I moused over one of the orbs and when my mouse icon changed, I knew the AI had made a move. It was almost faster to do it this way and search for the most recent move than to hope that I saw it done.

I feel like this would be a simple change that would help alleviate some of the pressure of working on this puzzle.

Lastly, thank you for changing the timer. When I managed to complete the achievement, I won with a score of 24-1 and, even with the extended timer, was very close to getting reset. It is invaluable to have those precious extra seconds to make a quick and informed decision instead of just wildly and blindly hitting anything you can.