Originally posted by Nefrarya:

I feel trolled.... The pause function came with the caves patch that was in beta, but was released to the main branch yesterday. Whatever key or controller button used to bring you to the main menu now pauses the game for a single player, as is the way.

Ah-HA! I didn't realize they released it yesterday to the main channel. Perhaps explains some weirdness I ran into with the mouse / FOV that has totally nerf'd my gameplay.
Now I need to check my version since I'm NOT on Beta channel.

Thanks!