Amazing amount of fun but also very short
The challenges are not the most difficult but they do ask for a little thought every now and again, especially towards the end of the game where you've got to be quick on the portal throwing. Whilst it is a very short game it is fun, maybe not as challenging as it could be but even despite that it is good fun and I think many people wouldn't appreciate it for the entertainment side if it was too hard.
In summary, yes it is a good game but you can tell it's an add-on to a larger package. Definitely worth a look, however brief it may be.