This is a good, bare bones version of iMovie and allows for all sorts of creative movie-making. Some features are disabled or significantly more difficult to use, though, because of the nature of working on an iPad. For example, this tool does not work well for stop-motion animation because it is automatically set to pan across all still photos (the “Ken Burns effect”). In the full version of iMovie, this effect is easy to disable. On the iPad, though, you have to manually set the beginning of the shot to be the same as the end of the shot (a rather time-consuming and tedious process) in order to work around the automatic panning across the image.
Also, importing videos from other sources can be extremely difficult because of file conversion issues.
In short, iMovie for the iPad is a great tool for making quick movies shot using the iPad (as camera) but I would not recommend it for stop-motion animation or for larger movie projects that require the importing of outside files.