I don't normally suffer from fits due to flashing lights, but as the day went on I felt ill whenever I completed a row/column or box. Those flashy-bits actually affected me... EPILEPTICS, BE WARNED!
Once you've completed all 200GP you can take time over the puzzles (and remove Auto Pencil) which helped.
I never managed to get any puzzles from the add-on (DLC), they were all from the 'standard' set.
-=#=- Speed-Run Achievement Walkthroughs -=#=-.