Reminded me of the Flint Stones, but had more present day technology. Which was kind of weird watching a caveman shower in the opening credits.
The graphics were pretty good. They were very detailed, and were pleasant to look at. It was odd though seeing that you basically used the same character models for the men and women. Still, the men looked like cavemen, but the cavewoman looked like they had oversized chins.
Sound was good, pleasant to hear with good voice acting. Nothing really much to say here, except you did a good job.
As for the humor, you didn't bring up anything new. It was basically a quick gay joke and then it was over. It seemed like a very odd mix having a gay caveman joke, but that's just me.
Improvements? Pick either prehistoric times or modern day. It just bugs the hell outta me watching a caveman shower, but they haven't mastered the wheel or surfboard yet. Unless they're cavemen in present day, so make that clear. Also, come up with better jokes please. That gay joke was too predictable.
Overall, good looking flash, but it lacks in the department it's focusing on.