If you take a single 720p frame, the resolution is about that of a 2 megapixel image. So no, it doesn't mean much. And it seems redundant to say, but I wish more people would understand that having 18 megapixels doesn't mean that the images are going to look nice. The Nikon D1, released over ten years ago, featured a 2.7 megapixel image sensor, and here's a photo from a D1:
Here's an image from Engadget of the Kin 2 which has an 8 megapixel sensor:
So please don't worry about how many megapixels it has. Anything over 5 is more than acceptable, especially with such a tiny lens and sensor.