Two-player game with Figures, with an extra achievement needed to win (so, 8 achievements needed).
I had much better luck with getting scoring cards than my opponent did, so I was able to zip through the normal achievements. Meanwhile, my opponent built up a much bigger tableau than mine, and he claimed several special achievements in the process.
Check out his turn 20. I was all set to claim the 8 achievement and win, but he managed to swipe my only level 8 card from my tableau. So I pondered... and eventually, my eyes landed on my Industrialization.
"I'm ahead on points. Can I end it now? If I share Industrialization, he'll tuck 8 cards and I'll tuck 3. That's 11 cards; if I do it twice, we'll tuck 22 cards. How many base cards are available to be tucked? Let's see... 21? PERFECT!"
Biggest shared Industrialization ever.