This had the energy of the late-stage (4 and 5) and trying-too-hard Scary Movie films.
The cock and ball jokes simply were never timely, nor funny. Besides those being somewhat crass, which isn't an issue, the jokes through out the movie felt rather tame and lacking the physical, absurdity, and word-play (save for the UCLA scene) of the original trilogy. It really seemed like they were afraid to be either too irreverent, too insensitive, or too violent. The audience was giving chuckles here and there. A Naked Gun flick should be getting way more out of them than that.
Violence? Yeah, this movie has it, but only in the same way a B-grade Bollywood film does, and not in a consistently funny way. Too much combat. They had an opportunity for an Airplane-esque old lady gag halfway in, but then (touching back to how timid most of the jokes felt), they cut it out. It only played out for an actual laugh in the first 5 minutes, and then the final "battle" near the end.
Pamela Anderson was spot on. Liam Neeson was good, but they really oughta let some of his "action hero" bravado go.