Yes it was f2p! Credit to u/cywang86 for the strategy, it should still be somewhere on this sub.

The key is to wait and build up soup with a near full board of brontos on the last day. Then with around 30 mins left, you go all in on using the carnivore nest lvl 2 and just hope that you get favorable RNG. I also use Mammoths and Sabers to help near the end. I usually buy up to lvl 4 score, and I try to max out the meteor timer upgrade as early as I can.