Guess it's fair to say that by now people are starting to be fed up with movies featuring old people playing old people, who are trying to be young again. It was something that was only popular for a short while and only worked out well in just an handful of movies. It must be part of the reason why this movie isn't really liked any better but in all fairness, it really isn't a bad movie at all.
It's simply a quite fun and entertaining movie really. It's obvious that Robert De Niro, Michael Douglas, Morgan Freeman and Kevin Kline all agreed to be in this not because they thought it would be a great movie but probably because they thought it would be one they could have a lot of fun with doing. And it shows. The liveliness of the 'old' cast blow live into the movie, that otherwise would have been a very mundane one.
The movie really isn't anything too solid or original but it still works out well for most part. The advantage of having a movie with 4 different main characters in it is that there is always going to be at least one that you are really going to like and sympathize with, for the movie its entire duration. And that's definitely the case with this movie as well. All characters are different enough ones but they all have something likable about them and they are easy to relate to, even when you aren't even remotely close to their age yet. It's because the movie in essence is about some very universal and 'ageless' themes really, such as friendship and love.
At the same time, the movie its main concept isn't as formulaic as it sounds though. It's not just a version of "The Hangover" only with older people in it, or one that's all about age jokes. It luckily still is a more creative movie than just that, even while not everything about it works out that well. Certain plot lines and developed are all too formulaic and predictable but the movie as a whole still manages to feel like a fresh and fun enough one.
And really, you think that a movie starring the likes of Robert De Niro, Michael Douglas, Morgan Freeman, Kevin Kline and Mary Steenburgen would be a bad one to watch? The movie is already worth watching for the acting alone. The 'old geezers' all play well of each other and their friendship is both convincing and believable.
I really can't image anybody ever calling this movie a brilliant or even genuinely great one but some movies are just there to enjoy, that you shouldn't nitpick to death and just enjoy them for what they are. I believe that "Last Vegas" is one of those movies. I never had a dull moment with it, despite of all of the formulaic ingredients. It's a fun and cute enough movie, that everybody should be able to enjoy, if they allow themselves to.