The first Ace Ventura was a micro-budget comedy film which became a cultural behemoth of its time, catapulting Jim Carrey to worldwide fame, his zany energy & perfect timing jumping out from the screen. Whilst for some people this humour is too over-the-top and try-hard, for me that is what I love so much about it, especially as everyone else around had never seen this level or type of out-there comedy in the mainstream before; (you could make a case for Andy Kaufman's work, but he was predominantly in the US, whereas Ace Ventura was worldwide.)
As this film still has many of the same themes, it is by it's very nature not a new/fresh idea, so there is an element of "We've seen this before." However, the film has made some fantastic decisions which prevent it from just being a rehash of everything that preceded it.
The most genius one in my opinion was bringing in Simon Callow as the main antagonist. Callow is quite simply one of the finest stage actors this country has ever and will ever produce, but he was known both for his extreme English-ness/being an upper class gentleman, as well as starring in Four Weddings and a Funeral. So when you put him, with all his traditional English mannerisms and speaking, opposite a completely unpredictable actor playing one of the most crazy characters ever dreamt up, it is comedic perfection. You feel that as much as Callow of course has the character he is playing, even as an actor he almost can't deal with Carrey. And this just makes it even funnier.
The zenith of this, as well as being one of the funniest things hands down I've ever seen in a film, which even today if I watch or think about it will make me laugh uncontrollably, is the "projector scene." The combination of silly, seriousness & stupidity will never be equalled. There is also a fantastically funny scene involving a dummy rhino which is hysterical.
The other good thing about this film is that, as it was the sequel to a massively successful movie, there is a very large budget which is generously used. The sets & locations are great and overall the film is brilliantly made, even more impressive when you consider that this was Steve Oedekirk's first film.
But, as with the first film, the level of enjoyment you will get from it depends entirely on if you find Carrey's brand of humour funny. If zany, outrageous and slapstick comedy really isn't your thing, then this will be a long 90 minutes for you. However if you loved the first film, then this is another, not quite as good, but still hugely funny romp.