While the box leads you to believe that
Diggles is similar to a number of other successful games, it is only a smokescreen for the game itself to infiltrate your computer as an imposter.
Diggles is only
Diggles, and nothing else, which in the end turns out to be not that great a thing.
Your job is to lead a group of dwarves on a mission to find Odin's lost dog, Fenris. This honor means you have the privilege of starting, supporting, and utilizing a clan of dwarves to complete a series of levels, unlimitedly ending up in the retrieval of Fenris.
The basic concept of getting around the levels is by digging. If you want to go somewhere, you have to dig, much like an ant in an ant farm. The tunnels you create are complimented by caves, which you also have to get your busy little dwarves to create. Caves give you more room for structures, which are also built by your short friends. The structures, such as tents and forges, allow you to create new items and more dwarves, basically the things that will help you complete the level.
Your dwarves are self-sufficient to an extent. They will automatically go and work on a job you have set, granted that they aren't on their leisure time. However, you have to set the tasks, like cooking food, or else the stupid little guys will sit around and do nothing. They have few needs that require attention, but if you neglect these important items, you'll find your population working slower, becoming weaker, and eventually dying.