Not good at all.
If this movie wasn't based on anything, maybe it would've done better. Unfortunately, it just so happens to be based on a cartoon from 1983. The sad part is how different it is from said cartoon. It does start off with some fancy CGI stuff, accompanied by an updated version of the 1983 theme song, which I thought was a nice touch. But it only goes down from there. First off, even the main character is different. He's not even that clumsy - which was a reason he usually won in the original. Also, the acting isn't that good. In the original, he was portrayed as incompetent, slight dim-witted, and simply lucky enough to get out of every situation alive. None of that is here.
My next big complaint is Dr. Claw. He was rather infamous for never showing his face (or rather any part of him besides his hand), and he's shown throughout the whole movie. Not just his face, everything is shown. You just can't do that.
Finally, Penny and Brain have very minor roles. Brain is basically a normal dog, and Penny's just there for whatever reason. In the cartoon, they were the real heroes. Whenever Gadget stumbled into something dangerous, Penny and Brain would secretly get him out of it and stop the bad guys, while making it look like Gadget did everything when the police arrive. In this movie, they actually don't do anything. Absolutely nothing.
So skip this one if you like the franchise as a whole, the old cartoon is a lot better, and much funnier. Please, watch that instead.
This title contains:
Violence & scariness