Some call that movie boring and dumb. Well, yes. And actually no. Yes, because it's really boring (it's not that entertaining, and the plot development is slow; though there will be quite an unexpected twist) and the plot is really dumb. But no, because that movie is not that simple.
Actually, I would not recommend this movie for kids. It's not about funny, fluffy, giant muppets. It's about death and losing your loved ones and how you actually go through that loss. And those IFs are kind of a way to cope with your loneliness and the emptiness in your heart. That movie is actually more sad than funny (seriously, at some moments I could barely hold back my tears). So, kids may have lots of questions after watching that movie.
To sum up: I liked that movie (not much, but). It wasn't as funny as I expected (all the jokes we saw in the trailer), but it turned out to be very emotional (which I didn't expect at all in the movie with Ryan Reynolds)