Is it possible to play this in offline mode?

[Yummy Tree Sap]

...and actually have your game save? I sure can't figure it out. Pretty infuriating, really.

On OS X, by the way, though I doubt it's much different.

[polar_rejection]

Yep; so long as you play it entirely offline. Once you launch the game connected to Steam it will load whatever is on the steamcloud. When you play offline your save content does not make it to the steamcloud.

At least this is what I've observed(running os x 10.6, steam package 1306976781)